MPLX MPLX Form 10-Q filing Q2 FY2024

Unless otherwise stated or the context otherwise indicates, all references in this Form 10-Q to “MPLX LP,” “MPLX,” “the Partnership,” “we,” “our,” “us,” or like terms refer to MPLX LP and its consolidated subsidiaries. References to our sponsor and customer, “MPC,” refer collectively to Marathon Petroleum Corporation and its subsidiaries, other than the Partnership.

Glossary of Terms

The abbreviations, acronyms and industry terminology used in this report are defined as follows:

ASC Accounting Standards Codification

ASU Accounting Standards Update

barrel One stock tank barrel, or 42 United States gallons of liquid volume, used in reference to crude oil or other liquid hydrocarbons

DCF (a non-GAAP financial measure) Distributable Cash Flow

EBITDA (a non-GAAP financial measure) Earnings Before Interest, Taxes, Depreciation and Amortization

FASB Financial Accounting Standards Board

FCF (a non-GAAP financial measure) Free Cash Flow

GAAP Accounting principles generally accepted in the United States of America

G&P Gathering and Processing segment

L&S Logistics and Storage segment

mbpd Thousand barrels per day

MMBtu One million British thermal units, an energy measurement

MMcf/d One million cubic feet per day

NGL Natural gas liquids, such as ethane, propane, butanes and natural gasoline

SEC United States Securities and Exchange Commission

SOFR Secured Overnight Financing Rate

VIE Variable interest entity

PART I—FINANCIAL INFORMATION

Item 1. Financial Statements

The accompanying notes are an integral part of these consolidated financial statements.

The accompanying notes are an integral part of these consolidated financial statements.

MPLX LP

Consolidated Balance Sheets (Unaudited)

The accompanying notes are an integral part of these consolidated financial statements.

The accompanying notes are an integral part of these consolidated financial statements.

The accompanying notes are an integral part of these consolidated financial statements.

Notes to Consolidated Financial Statements (Unaudited)

1. Description of the Business and Basis of Presentation

Description of the Business

MPLX LP is a diversified, large-cap master limited partnership formed by Marathon Petroleum Corporation that owns and operates midstream energy infrastructure and logistics assets, and provides fuels distribution services. We are engaged in the gathering, transportation, storage and distribution of crude oil, refined products, other hydrocarbon-based products and renewables; the gathering, processing and transportation of natural gas; and the transportation, fractionation, storage and marketing of NGLs. MPLX’s principal executive office is located in Findlay, Ohio. MPLX was formed on March 27, 2012 as a Delaware limited partnership and completed its initial public offering on October 31, 2012.

MPLX’s business consists of two segments based on the nature of services it offers: Logistics and Storage (“L&S”), which relates primarily to crude oil, refined products, other hydrocarbon-based products and renewables; and Gathering and Processing (“G&P”), which relates primarily to natural gas and NGLs. See Note 8 for additional information regarding the operations and results of these segments.

Basis of Presentation

These interim consolidated financial statements are unaudited; however, in the opinion of MPLX’s management, these statements reflect all adjustments necessary for a fair statement of the results for the periods reported. All such adjustments are of a normal, recurring nature unless otherwise disclosed. These interim consolidated financial statements, including the notes, have been prepared in accordance with the rules and regulations of the SEC applicable to interim period financial statements and do not include all of the information and disclosures required by GAAP for complete financial statements. Certain information derived from our audited annual financial statements, prepared in accordance with GAAP, has been condensed or omitted from these interim financial statements.

These interim consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto included in our Annual Report on Form 10-K for the year ended December 31, 2023. The results of operations for the three and six months ended June 30, 2024 are not necessarily indicative of the results to be expected for the full year.

MPLX’s consolidated financial statements include all majority-owned and controlled subsidiaries. For non-wholly owned consolidated subsidiaries, the interests owned by third parties have been recorded as Noncontrolling interests on the accompanying Consolidated Balance Sheets. Intercompany accounts and transactions have been eliminated. MPLX’s investments in which MPLX exercises significant influence but does not control and does not have a controlling financial interest are accounted for using the equity method. MPLX’s investments in VIEs in which MPLX exercises significant influence but does not control and is not the primary beneficiary are also accounted for using the equity method.

Certain prior period financial statement amounts have been reclassified to conform to current period presentation.

2. Accounting Standards and Disclosure Rules

Recently Adopted

During the first quarter of 2024, we adopted ASU 2023-01, Leases (Topic 842): Common Control Arrangements. The adoption of this ASU did not have a material impact on our financial statements or disclosures.

Not Yet Adopted

SEC Release No. 33-11275, The Enhancement and Standardization of Climate-Related Disclosures for Investors

In March 2024, the SEC adopted rules under SEC Release No. 33-11275, The Enhancement and Standardization of Climate-Related Disclosures for Investors, which requires registrants to provide certain climate-related information in their annual reports. As part of the disclosures, material impacts from severe weather events and other natural conditions will be required in the audited financial statements. In April 2024, the SEC voluntarily stayed the rules pending judicial review. Pending the results of the judicial review, the disclosure requirements are effective for the Partnership’s Annual Report on Form 10-K for the fiscal year ended December 31, 2025. We are evaluating the impact these rules will have on our disclosures and monitoring the status of the judicial review.

ASU 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures

In November 2023, the FASB issued an ASU to update reportable segment disclosure requirements primarily by requiring enhanced disclosures about significant segment expenses. This ASU is effective for fiscal years beginning after December 15, 2023, and for interim periods within fiscal years beginning after December 15, 2024. Early adoption is permitted. The amendments should be applied retrospectively to all prior periods presented in the financial statements. We are currently evaluating the impact this ASU will have on our disclosures.

3. Acquisitions and Other Transactions

Whistler Joint Venture Transaction

On May 29, 2024, MPLX and its joint venture partner contributed their respective membership interest in Whistler Pipeline, LLC to a newly formed joint venture, WPC Parent, LLC, and issued a 19 percent voting interest in WPC Parent, LLC to an affiliate of Enbridge Inc. in exchange for the contribution of cash and the Rio Bravo Pipeline project (collectively, the “Whistler Joint Venture Transaction”). As a result of the transaction, MPLX’s voting interest in the joint venture was reduced from 37.5 percent to 30.4 percent. MPLX recognized a gain of $151 million and received a cash distribution of $134 million, recorded as a return of capital, related to the dilution of the ownership interest. The gain is included in Income from equity method investments on the accompanying consolidated statements of income and the return of capital is included in Investments - redemptions, repayments, return of capital and sales proceeds within the investing section of the accompanying consolidated statements of cash flows.

Utica Midstream Acquisition

On March 22, 2024, MPLX used $625 million of cash on hand to purchase additional ownership interest in existing joint ventures and gathering assets (“Utica Midstream Acquisition”), which will enhance our position in the Utica basin. Prior to the acquisition, we owned an indirect interest in Ohio Gathering Company L.L.C. (“OGC”) and a direct interest in Ohio Condensate Company L.L.C. (“OCC”) and now own a combined 73 percent interest in OGC, a 100 percent interest in OCC, and a 100 percent interest in a dry gas gathering system in the Utica basin, including 53 miles of gathering pipeline and three dehydration units with a combined capacity of approximately 620 MMcf/d. OGC continues to be accounted for as an equity method investment, as MPLX did not obtain control of OGC as a result of the transaction. The acquisition date fair value of our investment in OGC exceeded our portion of the underlying net assets of the joint venture by approximately $86 million. OCC was previously accounted for as an equity method investment, and it is now reflected as a consolidated subsidiary within our consolidated financial results. The results for the acquired business are reported within our G&P segment.

The acquisition was accounted for as a business combination requiring all the acquired assets and liabilities to be remeasured to fair value resulting in a consolidated fair value of net assets and liabilities of $625 million. The fair value includes $518 million related to acquired interests in the joint ventures and the remaining balance related to other acquired assets and liabilities. The revaluation of MPLX’s existing 62 percent equity method investment in OCC resulted in a $20 million gain, which is included in Other income within the accompanying consolidated statements of income. The fair value of equity method investments was based on a discounted cash flow model.

4. Investments and Noncontrolling Interests

The following table presents MPLX’s equity method investments at the dates indicated:

(1) The investment in MarEn Bakken Company LLC includes our 9.19 percent indirect interest in a joint venture (“Dakota Access”) that owns and operates the Dakota Access Pipeline and Energy Transfer Crude Oil Pipeline projects (collectively, the “Bakken Pipeline system”).

(2) Reflects the dilution of MPLX’s ownership interest in Whistler Pipeline, LLC and the formation of a new entity, WPC Parent, LLC, as discussed in Note 3. The carrying value at June 30, 2024 represents our ownership in WPC Parent, LLC, and the carrying value at December 31, 2023 represents our ownership interest in Whistler Pipeline, LLC.

(3) Some investments included within Other have also been deemed to be VIEs.

(4) We acquired a 36 percent direct interest in OGC in the Utica Midstream Acquisition discussed in Note 3. We also hold a 37 percent indirect interest in OGC through our ownership interest in MarkWest Utica EMG, L.L.C.

For those entities that have been deemed to be VIEs, neither MPLX nor any of its subsidiaries have been deemed to be the primary beneficiary due to voting rights on significant matters. While we have the ability to exercise influence through participation in the management committees which make all significant decisions, we have equal influence over each committee as a joint interest partner and all significant decisions require the consent of the other investors without regard to economic interest. As such, we have determined that these entities should not be consolidated and applied the equity method of accounting with respect to our investments in each entity.

MPLX’s maximum exposure to loss as a result of its involvement with equity method investments generally includes its equity investment, any additional capital contribution commitments and any operating expenses incurred by the subsidiary operator in excess of its compensation received for the performance of the operating services. MPLX did not provide any financial support to equity method investments that it was not contractually obligated to provide during the six months ended June 30, 2024 and June 30, 2023. See Note 16 for information on our guarantees related to equity method investees.

5. Related Party Agreements and Transactions

MPLX engages in transactions with both MPC and certain of its equity method investments as part of its normal business; however, transactions with MPC make up the majority of MPLX’s related party transactions. Transactions with related parties are further described below.

MPLX has various long-term, fee-based commercial agreements with MPC. Under these agreements, MPLX provides transportation, gathering, terminal, fuels distribution, marketing, storage, management, operational and other services to MPC. MPC has committed to provide MPLX with minimum quarterly throughput volumes on crude oil and refined products and other fees for storage capacity; operating and management fees; and reimbursements for certain direct and indirect costs. MPC has also committed to provide a fixed fee for 100 percent of available capacity for boats, barges and third-party chartered equipment under the marine transportation service agreements. MPLX also has a keep-whole commodity agreement with MPC under which MPC pays us a processing fee for NGLs related to keep-whole agreements and we pay MPC a marketing fee in exchange for

assuming the commodity risk. In addition, MPLX has obligations to MPC for services provided to MPLX by MPC under omnibus and employee services type agreements as well as various other agreements.

During the second quarter of 2024, MPC exercised a five-year renewal option pursuant to the terms of an existing terminal services agreement with an initial term ending on March 31, 2026, with the term of the agreement now extending to 2031.The agreement includes both revenue and lease components. As a result of this renewal, minimum future rental payments on non-cancellable operating leases have increased $696 million, and minimum future undiscounted lease payment receipts under sales-type leases have increased $90 million. Future performance obligations for the revenue component of the agreement include variable consideration that is not required to be estimated.

Related Party Loan

MPLX is party to a loan agreement (the “MPC Loan Agreement”) with MPC. Under the terms of the MPC Loan Agreement, MPC extends loans to MPLX on a revolving basis as requested by MPLX and as agreed to by MPC. The borrowing capacity of the MPC Loan Agreement is $1.5 billion aggregate principal amount of all loans outstanding at any one time. The MPC Loan Agreement was renewed on July 31, 2024 and is now scheduled to expire, and borrowings under the loan agreement are scheduled to mature and become due and payable, on July 31, 2029, provided that MPC may demand payment of all or any portion of the outstanding principal amount of the loan, together with all accrued and unpaid interest and other amounts (if any), at any time prior to maturity. Borrowings under the MPC Loan Agreement bear interest at one-month term SOFR adjusted upward by 0.10 percent plus 1.25 percent or such lower rate as would be applicable to such loans under the MPLX Credit Agreement as discussed in Note 12.

There was no activity on the MPC Loan Agreement for the six months ended June 30, 2024.

Related Party Revenue

Related party sales to MPC primarily consist of crude oil and refined products pipeline services based on tariff or contracted rates; storage, terminal and fuels distribution services based on contracted rates; and marine transportation services. Related party sales to MPC also consist of revenue related to volume deficiency credits.

MPLX also has operating agreements with MPC under which it receives a fee for operating MPC’s retained pipeline assets and a fixed annual fee for providing oversight and management services required to run the marine business. MPLX also receives management fee revenue for engineering, construction and administrative services for operating certain of its equity method investments. Amounts earned under these agreements are classified as Other income - related parties in the Consolidated Statements of Income.

Certain product sales to MPC and other related parties net to zero within the consolidated financial statements as the transactions are recorded net due to the terms of the agreements under which such product was sold. For the three and six months ended June 30, 2024, these sales totaled $182 million and $384 million, respectively. For the three and six months ended June 30, 2023, these sales totaled $150 million and $348 million, respectively.

Related Party Expenses

MPC charges MPLX for executive management services and certain general and administrative services provided to MPLX under the terms of our omnibus agreements (“Omnibus charges”) and for certain employee services provided to MPLX under employee services agreements (“ESA charges”). Omnibus charges and ESA charges are classified as Rental cost of sales - related parties, Purchases - related parties, or General and administrative expenses depending on the nature of the asset or activity with which the costs are associated. In addition to these agreements, MPLX purchases products from MPC, makes payments to MPC in its capacity as general contractor to MPLX, and has certain rent and lease agreements with MPC.

For the three and six months ended June 30, 2024, General and administrative expenses incurred from MPC totaled $71 million and $144 million, respectively. For the three and six months ended June 30, 2023, General and administrative expenses incurred from MPC totaled $61 million and $125 million, respectively.

Some charges incurred under the omnibus, employee service and co-location agreements are related to engineering and construction services and are associated with assets under construction. These charges are added to Property, plant and equipment, net on the Consolidated Balance Sheets. For the three and six months ended June 30, 2024, these charges totaled $39 million and $80 million, respectively. For the three and six months ended June 30, 2023, these charges totaled $18 million and $28 million, respectively.

Related Party Assets and Liabilities

Assets and liabilities with related parties appearing in the Consolidated Balance Sheets are detailed in the table below. This table identifies the various components of related party assets and liabilities, including those associated with leases and deferred revenue on minimum volume commitments. If MPC fails to meet its minimum committed volumes, MPC will pay MPLX a deficiency payment based on the terms of the agreement. The deficiency amounts received under these agreements (excluding payments received under agreements classified as sales-type leases) are recorded as Current liabilities - related parties. In many cases, MPC may then apply the amount of any such deficiency payments as a credit for volumes in excess of its minimum volume commitment in future periods under the terms of the applicable agreements. MPLX recognizes related party revenues for

the deficiency payments when credits are used for volumes in excess of minimum quarterly volume commitments, where it is probable the customer will not use the credit in future periods or upon the expiration of the credits. The use or expiration of the credits is a decrease in Current liabilities - related parties. Deficiency payments under agreements that have been classified as sales-type leases are recorded as a reduction against the corresponding lease receivable. In addition, capital projects MPLX undertakes at the request of MPC are reimbursed in cash and recognized as revenue over the remaining term of the applicable agreements or in some cases, as a contribution from MPC.

(1) There were no borrowings outstanding on the MPC Loan Agreement as of June 30, 2024 or December 31, 2023.

6. Equity

The changes in the number of common units during the six months ended June 30, 2024 are summarized below:

Unit Repurchase Program

On August 2, 2022, we announced the board authorization for the repurchase of up to $1 billion of MPLX common units held by the public. This unit repurchase authorization has no expiration date. We may utilize various methods to effect the repurchases, which could include open market repurchases, negotiated block transactions, accelerated unit repurchases, tender offers or open market solicitations for units, some of which may be effected through Rule 10b5-1 plans. The timing and amount of future repurchases, if any, will depend upon several factors, including market and business conditions, and such repurchases may be suspended, discontinued or restarted at any time.

Total unit repurchases were as follows for the respective periods:

(1) Cash paid for common units repurchased and average cost per unit includes commissions paid to brokers during the period.

As of June 30, 2024, we had $696 million remaining under the unit repurchase authorization.

Series A Redeemable Preferred Unit Conversions

During the three and six months ended June 30, 2024, certain Series A preferred unitholders exercised their rights to convert their Series A preferred units into approximately 11 million common units and 21 million common units, respectively. Approximately 6 million Series A preferred units remain outstanding as of June 30, 2024.

Redemption of the Series B Preferred Units

On February 15, 2023, MPLX exercised its right to redeem all 600,000 outstanding 6.875 percent Fixed-to-Floating Rate Cumulative Redeemable Perpetual Preferred Units (the “Series B preferred units”). MPLX paid unitholders the Series B preferred unit redemption price of $1,000 per unit. MPLX made a final cash distribution of $21 million to Series B preferred unitholders on February 15, 2023, in conjunction with the redemption.

Distributions

On July 30, 2024, MPLX declared a cash distribution for the second quarter of 2024, totaling $868 million, or $0.850 per common unit. This distribution will be paid on August 16, 2024 to common unitholders of record on August 9, 2024. This rate will also be received by Series A preferred unitholders.

Quarterly distributions for 2024 and 2023 are summarized below:

The allocation of total quarterly cash distributions to common and preferred unitholders is as follows for the three and six months ended June 30, 2024 and June 30, 2023. Distributions, although earned, are not accrued until declared. MPLX’s distributions are declared subsequent to quarter end; therefore, the following table represents total cash distributions applicable to the period in which the distributions were earned.

(1) The six months ended June 30, 2023 includes the portion of the $21 million distribution paid to the Series B preferred unitholders on February 15, 2023 that was earned during the period prior to redemption.

7. Net Income Per Limited Partner Unit

Net income per unit applicable to common units is computed by dividing net income attributable to MPLX LP less income allocated to participating securities by the weighted average number of common units outstanding.

During the three and six months ended June 30, 2024 and June 30, 2023, MPLX had participating securities consisting of common units, certain equity-based compensation awards, Series A preferred units, and Series B preferred units and also had dilutive potential common units consisting of certain equity-based compensation awards. Potential common units omitted from the diluted earnings per unit calculation for the three and six months ended June 30, 2024 and June 30, 2023 were less than 1 million.

(1) Allocation of net income attributable to MPLX LP assumes all earnings for the period have been distributed based on the distribution priorities applicable to the period.

8. Segment Information

MPLX’s chief operating decision maker (“CODM”) is the chief executive officer of its general partner. The CODM reviews MPLX’s discrete financial information, makes operating decisions, assesses financial performance and allocates resources on a type of service basis. MPLX has two reportable segments: L&S and G&P. Each of these segments is organized and managed based upon the nature of the products and services it offers.

• L&S – gathers, transports, stores and distributes crude oil, refined products, other hydrocarbon-based products and renewables. Also includes the operation of refining logistics, fuels distribution and inland marine businesses, terminals, rail facilities, and storage caverns.
• G&P – gathers, processes and transports natural gas; and transports, fractionates, stores and markets NGLs.

Our CODM evaluates the performance of our segments using Segment Adjusted EBITDA. Amounts included in net income and excluded from Segment Adjusted EBITDA include: (i) depreciation and amortization; (ii) net interest and other financial costs; (iii) income/(loss) from equity method investments; (iv) distributions and adjustments related to equity method investments; (v) impairment expense; (vi) noncontrolling interests; and (vii) other adjustments, as applicable. These items are either: (i) believed to be non-recurring in nature; (ii) not believed to be allocable or controlled by the segment; or (iii) are not tied to the operational performance of the segment. Assets by segment are not a measure used to assess the performance of the Partnership by our CODM and thus are not reported in our disclosures.

The tables below present information about revenues and other income, Segment Adjusted EBITDA, capital expenditures and investments in unconsolidated affiliates for our reportable segments:

(1) Within the total segment revenues and other income amounts presented above, third party revenues for the L&S segment were $376 million and $583 million for the three and six months ended June 30, 2024, respectively, and $187 million and $357 million for the three and six months ended June 30, 2023, respectively. Third party revenues for the G&P segment were $1,208 million and $2,420 million for the three and six months ended June 30, 2024, respectively, and $1,139 million and $2,305 million for the three and six months ended June 30, 2023, respectively.

(2) See below for the reconciliation from Segment Adjusted EBITDA to Net income.

(3) The six months ended June 30, 2024 includes a contribution of $92 million to Dakota Access to fund our share of a debt repayment by the joint venture.

The table below provides a reconciliation of Segment Adjusted EBITDA for reportable segments to Net income.

(1) Depreciation and amortization attributable to L&S was $131 million and $261 million for the three and six months ended June 30, 2024, respectively, and $140 million and $269 million for the three and six months ended June 30, 2023, respectively. Depreciation and amortization attributable to G&P was $189 million and $376 million for the three and six months ended June 30, 2024, respectively, and $170 million and $337 million for the three and six months ended June 30, 2023, respectively.

(2) Includes unrealized derivative gain/(loss), equity-based compensation, provision for income taxes, and other miscellaneous items.

9. Property, Plant and Equipment

Property, plant and equipment with associated accumulated depreciation is shown below:

10. Fair Value Measurements

Fair Values – Recurring

The following table presents the impact on the Consolidated Balance Sheets of MPLX’s financial instruments carried at fair value on a recurring basis as of June 30, 2024 and December 31, 2023 by fair value hierarchy level.

Level 2 instruments include over-the-counter fixed swaps to mitigate the price risk from our sales of propane under certain percent-of-proceeds and keep-whole arrangements. The swap valuations are based on observable inputs in the form of forward prices based on Mont Belvieu propane forward spot prices and contain no significant unobservable inputs.

Level 3 instruments relate to an embedded derivative liability for a natural gas purchase commitment embedded in a keep-whole processing agreement. The fair value calculation for these Level 3 instruments used significant unobservable inputs including: (1) NGL prices interpolated and extrapolated due to inactive markets ranging from $0.67 to $1.58 per gallon with a weighted average of $0.85 per gallon and (2) a 100 percent probability of renewal for the five-year renewal term of the gas purchase commitment and related keep-whole processing agreement. Increases or decreases in the fractionation spread result in an increase or decrease in the fair value of the embedded derivative liability, respectively.

Changes in Level 3 Fair Value Measurements

The following table is a reconciliation of the net beginning and ending balances recorded for net liabilities classified as Level 3 in the fair value hierarchy.

(1) (Loss)/gain on derivatives embedded in commodity contracts are recorded in Purchased product costs in the Consolidated Statements of Income.

Fair Values – Non-recurring

Non-recurring fair value measurements and disclosures in 2024 relate to the Whistler Joint Venture Transaction and the purchase of additional ownership interest in existing joint ventures and gathering assets as discussed in Note 3.

Fair Values – Reported

We believe the carrying value of our other financial instruments, including cash and cash equivalents, receivables, receivables from related parties, lease receivables, lease receivables from related parties, accounts payable, and payables to related parties, approximate fair value. MPLX’s fair value assessment incorporates a variety of considerations, including the duration of the instruments, MPC’s investment-grade credit rating, and the historical incurrence of and expected future insignificance of bad debt expense, which includes an evaluation of counterparty credit risk. The recorded value of the amounts outstanding under the bank revolving credit facility, if any, approximates fair value due to the variable interest rate that approximates current market rates. Derivative instruments are recorded at fair value, based on available market information (see Note 11).

The fair value of MPLX’s debt is estimated based on prices from recent trade activity and is categorized in Level 3 of the fair value hierarchy. The following table summarizes the fair value and carrying value of our third-party debt, excluding finance leases and unamortized debt issuance costs:

(1) Any amounts outstanding under the MPC Loan Agreement are not included in the table above, as the carrying value approximates fair value. This balance is reflected in Current liabilities - related parties in the Consolidated Balance Sheets.

11. Derivatives

As of June 30, 2024, MPLX had the following outstanding commodity contracts that were executed to manage the price risk associated with sales of propane under certain percent-of-proceeds and keep-whole arrangements during 2024. Any gains or losses on these contracts are recorded in earnings through Product sales in the Consolidated Statements of Income:

(In millions) June 30, 2024 December 31, 2023

Assets

Cash and cash equivalents $2,501 $1,048

Receivables, net 747 823

Current assets - related parties 748 748

Inventories 168 159

Other current assets 32 30

Total current assets 4,196 2,808

Equity method investments 4,373 3,743

Property, plant and equipment, net 19,186 19,264

Intangibles, net 585 654

Goodwill 7,645 7,645

Right of use assets, net 282 264

Noncurrent assets - related parties 1,160 1,161

Other noncurrent assets 975 990

Total assets 38,402 36,529

Liabilities

Accounts payable 127 153

Accrued liabilities 246 300

Current liabilities - related parties 344 360

Accrued property, plant and equipment 172 216

Long-term debt due within one year 2,827 1,135

Accrued interest payable 252 242

Operating lease liabilities 50 45

Other current liabilities 208 173

Total current liabilities 4,226 2,624

Long-term deferred revenue 344 347

Long-term liabilities - related parties 325 325

Long-term debt 19,245 19,296

Deferred income taxes 16 16

Long-term operating lease liabilities 225 211

Other long-term liabilities 135 126

Total liabilities 24,516 22,945

Commitments and contingencies (see Note 16)

Series A preferred units (6 million and 27 million units outstanding) 202 895

Equity

Common unitholders - public (374 million and 356 million units outstanding) 9,392 8,700

Common unitholders - MPC (647 million and 647 million units outstanding) 4,062 3,758

Accumulated other comprehensive loss (3) (4)

Total MPLX LP partners’ capital 13,451 12,454

Noncontrolling interests 233 235

Total equity 13,684 12,689

Total liabilities, preferred units and equity $38,402 $36,529

Derivative contracts not designated as hedging instruments Financial Position Notional Quantity

Propane (gal) Short 28,904,000

Embedded Derivative - MPLX has a natural gas purchase commitment embedded in a keep-whole processing agreement with a producer customer in the Southern Appalachia region expiring in December 2027. The customer has the unilateral option to extend the agreement for one five-year term through December 2032. For accounting purposes, the natural gas purchase commitment and the term extending option have been aggregated into a single compound embedded derivative. The probability of the customer exercising its option is determined based on assumptions about the customer’s potential business strategy decision points that may exist at the time they would elect whether to renew the contract. The changes in fair value of this compound embedded derivative are based on the difference between the contractual and index pricing, the probability of the producer customer exercising its option to extend, and the estimated favorability of these contracts compared to current market conditions. The changes in fair value are recorded in earnings through Purchased product costs in the Consolidated Statements of Income. For further information regarding the fair value measurement of derivative instruments, see Note 10. As of June 30, 2024 and December 31, 2023, the estimated fair value of this contract was a liability of $69 million and $61 million, respectively.

Certain derivative positions are subject to master netting agreements; therefore, MPLX has elected to offset derivative assets and liabilities that are legally permissible to be offset. As of June 30, 2024 and December 31, 2023, there were no derivative assets or liabilities that were offset in the Consolidated Balance Sheets.

We make a distinction between realized or unrealized gains and losses on derivatives. During the period when a derivative contract is outstanding, changes in the fair value of the derivative are recorded as an unrealized gain or loss. When a derivative contract matures or is settled, the previously recorded unrealized gain or loss is reversed, and the realized gain or loss of the contract is recorded. The impact of MPLX’s derivative contracts not designated as hedging instruments and the location of gains and losses recognized in the Consolidated Statements of Income is summarized below:

12. Debt

MPLX’s outstanding borrowings consist of the following:

Credit Agreement

MPLX’s credit agreement (the “MPLX Credit Agreement”) matures in July 2027 and, among other things, provides for a $2 billion unsecured revolving credit facility and letter of credit issuing capacity under the facility of up to $150 million. Letter of credit issuing capacity is included in, not in addition to, the $2 billion borrowing capacity. Borrowings under the MPLX Credit Agreement bear interest, at MPLX’s election, at either the Adjusted Term SOFR or the Alternate Base Rate, both as defined in the MPLX Credit Agreement, plus an applicable margin.

There was no activity on the MPLX Credit Agreement during the six months ended June 30, 2024.

Fixed Rate Senior Notes

MPLX’s senior notes, including those issued by consolidated subsidiaries, consist of various series of senior notes maturing between 2024 and 2058 with interest rates ranging from 1.750 percent to 5.650 percent. Interest on each series of notes is payable semi-annually in arrears on various dates depending on the series of the notes.

On May 20, 2024, MPLX issued $1.65 billion aggregate principal amount of 5.50 percent senior notes due 2034 (the “2034 Senior Notes”) in an underwritten public offering. The 2034 Senior Notes were offered at a price to the public of 98.778 percent of par, with interest payable semi-annually in arrears, commencing on December 1, 2024. MPLX intends to use the net proceeds from the issuance of the 2034 Senior Notes to repay, redeem, or otherwise retire some or all of (i) MPLX’s outstanding $1,149 million aggregate principal amount of 4.875 percent senior notes due December 2024, (ii) MarkWest’s outstanding $1 million aggregate principal amount of 4.875 percent senior notes due December 2024 and (iii) MPLX’s outstanding $500 million aggregate principal amount of 4.000 percent senior notes due February 2025, and in the interim may use such net proceeds for general partnership purposes.

13. Net Interest and Other Financial Costs

Net interest and other financial costs were as follows:

14. Revenue

Disaggregation of Revenue

The following tables represent a disaggregation of revenue for each reportable segment for the three and six months ended June 30, 2024 and June 30, 2023:

(1) Non-ASC 606 Revenue includes rental income, sales-type lease revenue, income from equity method investments, and other income.

Contract Balances

Our receivables are primarily associated with customer contracts. Payment terms vary by product or service type; however, the period between invoicing and payment is not significant. Included within the receivables are balances related to commodity sales on behalf of our producer customers, for which we remit the net sales price back to the producer customers upon completion of the sale.

Under certain of our contracts, we recognize revenues in excess of billings which we present as contract assets. Contract assets typically relate to deficiency payments related to minimum volume commitments and aid in construction agreements where the revenue recognized and MPLX’s rights to consideration for work completed exceeds the amount billed to the customer. Contract assets are included in Other current assets and Other noncurrent assets on the Consolidated Balance Sheets.

Under certain of our contracts, we receive payments in advance of satisfying our performance obligations, which are recorded as contract liabilities. Contract liabilities, which we present as Deferred revenue and Long-term deferred revenue, typically relate to advance payments for aid in construction agreements and deferred customer credits associated with makeup rights and minimum volume commitments. Related to minimum volume commitments, breakage is estimated and recognized into service revenue in instances where it is probable the customer will not use the credit in future periods. We classify contract liabilities as current or long-term based on the timing of when we expect to recognize revenue.

The tables below reflect the changes in ASC 606 contract balances for the six months ended June 30, 2024 and June 30, 2023:

(1) No significant revenue was recognized related to past performance obligations in the current periods.

Remaining Performance Obligations

The table below includes estimated revenue expected to be recognized in the future related to performance obligations that are unsatisfied (or partially unsatisfied) as of June 30, 2024. The amounts presented below are generally limited to fixed consideration from contracts with customers that contain minimum volume commitments.

A significant portion of our future contracted revenue is excluded from the amounts presented below in accordance with ASC 606. Variable consideration that is constrained or not required to be estimated as it reflects our efforts to perform is excluded from this disclosure. Additionally, we do not disclose information on the future performance obligations for any contract with an original expected duration of one year or less, or that are terminable by our customer with little or no termination penalties. Potential future performance obligations related to renewals that have not yet been exercised or are not certain of exercise are

excluded from the amounts presented below. Revenues classified as Rental income and Sales-type lease revenue are also excluded from this table.

As of June 30, 2024, unsatisfied performance obligations included in the Consolidated Balance Sheets are $505 million and will be recognized as revenue as the obligations are satisfied, which is generally expected to occur over the next 20 years. A portion of this amount is not disclosed in the table above as it is deemed variable consideration due to volume variability.

15. Supplemental Cash Flow Information

The Consolidated Statements of Cash Flows exclude changes to the Consolidated Balance Sheets that do not affect cash. The following is a reconciliation of additions to property, plant and equipment to total capital expenditures:

16. Commitments and Contingencies

MPLX is the subject of, or a party to, a number of pending or threatened legal actions, contingencies and commitments involving a variety of matters, including laws and regulations relating to the environment. Some of these matters are discussed below. For matters for which MPLX has not recorded a liability, MPLX is unable to estimate a range of possible loss because the issues involved have not been fully developed through pleadings, discovery or court proceedings. However, the ultimate resolution of some of these contingencies could, individually or in the aggregate, be material.

Environmental Matters

MPLX is subject to federal, state and local laws and regulations relating to the environment. These laws generally provide for control of pollutants released into the environment and require responsible parties to undertake remediation of hazardous waste disposal sites. Penalties may be imposed for non-compliance.

Accrued liabilities for remediation totaled $16 million at June 30, 2024 and $19 million December 31, 2023. It is not presently possible to estimate the ultimate amount of all remediation costs that might be incurred or the penalties, if any, that may be imposed.

MPLX is involved in environmental enforcement matters arising in the ordinary course of business. While the outcome and impact to MPLX cannot be predicted with certainty, management believes the resolution of these environmental matters will not, individually or collectively, have a material adverse effect on its consolidated results of operations, financial position or cash flows.

Other Legal Proceedings

In July 2020, Tesoro High Plains Pipeline Company, LLC (“THPP”), a subsidiary of MPLX, received a Notification of Trespass Determination from the Bureau of Indian Affairs (“BIA”) relating to a portion of the Tesoro High Plains Pipeline that crosses the Fort Berthold Reservation in North Dakota. The notification demanded the immediate cessation of pipeline operations and assessed trespass damages of approximately $187 million. After subsequent appeal proceedings and in compliance with a new order issued by the BIA, in December 2020, THPP paid approximately $4 million in assessed trespass damages and ceased use of the portion of the pipeline that crosses the property at issue. In March 2021, the BIA issued an order purporting to vacate the BIA's prior orders related to THPP’s alleged trespass and direct the Regional Director of the BIA to reconsider the issue of THPP’s alleged trespass and issue a new order. In April 2021, THPP filed a lawsuit in the District of North Dakota against the United States of America, the U.S. Department of the Interior and the BIA (collectively, the “U.S. Government Parties”) challenging the March 2021 order purporting to vacate all previous orders related to THPP’s alleged trespass. On February 8, 2022, the U.S. Government Parties filed their answer and counterclaims to THPP’s suit claiming THPP is in continued trespass with respect to the pipeline and seeking disgorgement of pipeline profits from June 1, 2013 to present, removal of the pipeline and remediation. On November 8, 2023, the District Court of North Dakota granted THPP’s motion to sever and stay the U.S. Government Parties’ counterclaims. The case will proceed on the merits of THPP’s challenge to the March 2021 order purporting to vacate all previous orders related to THPP’s alleged trespass. THPP continues not to operate that portion of the pipeline that crosses the property at issue.

MPLX is also a party to a number of other lawsuits and other proceedings arising in the ordinary course of business. While the ultimate outcome and impact to MPLX cannot be predicted with certainty, management believes the resolution of these other lawsuits and proceedings will not, individually or collectively, have a material adverse effect on its consolidated financial position, results of operations or cash flows.

Guarantees related to indebtedness of equity method investees

We hold a 9.19 percent indirect interest in Dakota Access, which owns and operates the Bakken Pipeline system. In 2020, the U.S. District Court for the District of Columbia (the “D.D.C.”) ordered the United States Army Corps of Engineers (“Army Corps”), which granted permits and an easement for the Bakken Pipeline system, to prepare an environmental impact statement (“EIS”) relating to an easement under Lake Oahe in North Dakota. The D.D.C. later vacated the easement. The Army Corps issued a draft EIS in September 2023 detailing various options for the easement going forward, including denying the easement, approving the easement with additional measures, rerouting the easement, or approving the easement with no changes. The Army Corps has not selected a preferred alternative, but will make a decision in its final review, after considering input from the public and other agencies. The pipeline remains operational while the Army Corps finalizes its decision which is expected to be issued by the end of 2024.

We have entered into a Contingent Equity Contribution Agreement whereby MPLX LP, along with the other joint venture owners in the Bakken Pipeline system, has agreed to make equity contributions to the joint venture upon certain events occurring to allow the entities that own and operate the Bakken Pipeline system to satisfy their senior note payment obligations. The senior notes were issued to repay amounts owed by the pipeline companies to fund the cost of construction of the Bakken Pipeline system.

If the vacatur of the easement results in a temporary shutdown of the pipeline, MPLX would have to contribute its 9.19 percent pro rata share of funds required to pay interest accruing on the notes and any portion of the principal that matures while the pipeline is shut down. MPLX also expects to contribute its 9.19 percent pro rata share of any costs to remediate any deficiencies to reinstate the easement and/or return the pipeline into operation. If the vacatur of the easement results in a permanent shutdown of the pipeline, MPLX would have to contribute its 9.19 percent pro rata share of the cost to redeem the bonds (including the one percent redemption premium required pursuant to the indenture governing the notes) and any accrued and unpaid interest. As of June 30, 2024, our maximum potential undiscounted payments under the Contingent Equity Contribution Agreement were approximately $78 million.

Other guarantees

MPLX’s maximum exposure to loss for WPC Parent, LLC includes an $82 million commitment to indemnify a joint venture member for our pro rata share of any payments made under a performance guarantee for construction of a pipeline by an equity method investee.

Contractual Commitments and Contingencies

From time to time and in the ordinary course of business, MPLX and its affiliates provide guarantees of MPLX’s subsidiaries payment and performance obligations in the G&P segment. Certain natural gas processing and gathering arrangements require MPLX to construct natural gas processing plants, natural gas gathering pipelines and NGL pipelines and contain certain fees and charges if specified construction milestones are not achieved for reasons other than force majeure. In certain cases, certain

producers may have the right to cancel the processing arrangements if there are significant delays that are not due to force majeure. As of June 30, 2024, management does not believe there are any indications that MPLX will not be able to meet the construction milestones, that force majeure does not apply or that such fees and charges will otherwise be triggered.

Item 2. Management’s Discussion and Analysis of Financial Condition and Results of Operations

Management’s Discussion and Analysis of Financial Condition and Results of Operations should also be read in conjunction with the unaudited consolidated financial statements and accompanying footnotes included under Item 1. Financial Statements and in conjunction with our Annual Report on Form 10-K for the year ended December 31, 2023.

non-GAAP financial measures of Adjusted EBITDA, DCF, adjusted free cash flow (“Adjusted FCF”), and Adjusted FCF after distributions.

Adjusted EBITDA is a financial performance measure used by management, industry analysts, investors, lenders, and rating agencies to assess the financial performance and operating results of our ongoing business operations. Additionally, we believe adjusted EBITDA provides useful information to investors for trending, analyzing and benchmarking our operating results from period to period as compared to other companies that may have different financing and capital structures. We define Adjusted EBITDA as net income adjusted for: (i) provision for income taxes; (ii) net interest and other financial costs; (iii) depreciation and amortization; (iv) income/(loss) from equity method investments; (v) distributions and adjustments related to equity method investments; (vi) impairment expense; (vii) noncontrolling interests; and (viii) other adjustments, as applicable.

DCF is a financial performance and liquidity measure used by management and by the board of directors of our general partner as a key component in the determination of cash distributions paid to unitholders. We believe DCF is an important financial measure for unitholders as an indicator of cash return on investment and to evaluate whether the partnership is generating sufficient cash flow to support quarterly distributions. In addition, DCF is commonly used by the investment community because the market value of publicly traded partnerships is based, in part, on DCF and cash distributions paid to unitholders. We define DCF as Adjusted EBITDA adjusted for: (i) deferred revenue impacts; (ii) sales-type lease payments, net of income; (iii) adjusted net interest and other financial costs; (iv) net maintenance capital expenditures; (v) equity method investment capital expenditures paid out; and (vi) other adjustments as deemed necessary.

Adjusted FCF and Adjusted FCF after distributions are financial liquidity measures used by management in the allocation of capital and to assess financial performance. We believe that unitholders may use this metric to analyze our ability to manage leverage and return capital. We define Adjusted FCF as net cash provided by operating activities adjusted for: (i) net cash used in investing activities; (ii) cash contributions from MPC; and (iii) cash distributions to noncontrolling interests. We define Adjusted FCF after distributions as Adjusted FCF less base distributions to common and preferred unitholders.

We believe that the presentation of Adjusted EBITDA, DCF, Adjusted FCF and Adjusted FCF after distributions provides useful information to investors in assessing our financial condition and results of operations. The GAAP measures most directly comparable to Adjusted EBITDA and DCF are net income and net cash provided by operating activities while the GAAP measure most directly comparable to Adjusted FCF and Adjusted FCF after distributions is net cash provided by operating activities. These non-GAAP financial measures should not be considered alternatives to net income or net cash provided by operating activities as they have important limitations as analytical tools because they exclude some but not all items that affect net income and net cash provided by operating activities or any other measure of financial performance or liquidity presented in accordance with GAAP. These non-GAAP financial measures should not be considered in isolation or as substitutes for analysis of our results as reported under GAAP. Additionally, because non-GAAP financial measures may be defined differently by other companies in our industry, our definitions may not be comparable to similarly titled measures of other companies, thereby diminishing their utility. For a reconciliation of Adjusted EBITDA and DCF to their most directly comparable measures calculated and presented in accordance with GAAP, see Results of Operations. For a reconciliation of Adjusted FCF and Adjusted FCF after distributions to their most directly comparable measure calculated and presented in accordance with GAAP, see Liquidity and Capital Resources.

Results of Operations

The following tables and discussion summarize our results of operations, including a reconciliation of Adjusted EBITDA and DCF from Net income and Net cash provided by operating activities, the most directly comparable GAAP financial measures. This discussion should be read in conjunction with Item 1. Financial Statements and is intended to provide investors with a reasonable basis for assessing our historical operations, but should not serve as the only criteria for predicting our future performance.

(1) Non-GAAP measure. See reconciliation below to the most directly comparable GAAP measures.

(1) Includes unrealized derivative gain/(loss), equity-based compensation and other miscellaneous items.

(2) Represents Net interest and other financial costs excluding gain/loss on extinguishment of debt and amortization of deferred financing costs.

(1) Represents Net interest and other financial costs excluding gain/loss on extinguishment of debt and amortization of deferred financing costs.

Three months ended June 30, 2024 compared to three months ended June 30, 2023

Total revenues and other income increased $362 million in the second quarter of 2024 compared to the same period of 2023. The increase was driven by higher pipeline tariffs and higher throughput from equity method investments in the L&S segment, higher NGL prices and volumes within the G&P segment, and incremental revenues from the consolidation of MarkWest Torñado GP, L.L.C. (“Torñado”) in December 2023 (the “Torñado Acquisition”) and the acquisition of additional ownership interest in existing joint ventures and gathering assets in the Utica basin (the “Utica Midstream Acquisition”) that was completed in the first quarter of 2024. The 2024 increase also includes a $151 million gain related to the dilution of our ownership interest in connection with the Whistler Joint Venture Transaction.

Cost of revenues increased $36 million in the second quarter of 2024 compared to the same period of 2023. The increase is attributable to higher operating costs and repairs and maintenance costs and an increase of $10 million as a result of the consolidation of Torñado in December 2023.

Purchased product costs increased $22 million in the second quarter of 2024 compared to the same period of 2023. This was primarily due to higher NGL prices of $34 million partially offset by lower NGL volumes of $15 million.

Purchases - related parties increased $31 million in the second quarter of 2024 compared to the same period of 2023. This was primarily due to increased transportation costs in the G&P segment and changes in presentation driven by modification of an agreement with MPC.

General and administrative expenses increased $18 million in the second quarter of 2024 compared to the same period of 2023, due to increased contractor services costs and higher employee costs from MPC.

Six months ended June 30, 2024 compared to six months ended June 30, 2023

Total revenues and other income increased $495 million in the first six months of 2024 compared to the same period of 2023. This was primarily due to higher pipeline tariff rates within in the L&S segment, higher volumes and higher throughput fee rates within the G&P segment, and incremental revenues from the consolidation of Torñado in December 2023 and the Utica

Midstream Acquisition that was completed in the first quarter of 2024. The increase also includes a $151 million gain related to the Whistler Joint Venture Transaction, a $25 million benefit from business interruption insurance proceeds and a $20 million gain related to an equity method investment acquisition in the first quarter of 2024. Income from equity method investments also benefited from increased throughput on equity method investment pipeline systems in the 2024 period.

Cost of revenues increased $99 million in the first six months of 2024 compared to the same period of 2023. This was primarily attributable to higher operating costs and repairs and maintenance costs and an increase of $24 million as a result of the consolidation of Torñado in December 2023.

Purchased product costs decreased $15 million in the first six months of 2024 compared to the same period of 2023. The decrease was due to lower NGL volumes of $36 million, partially offset by higher NGL prices of $16 million.

Purchases - related parties increased $42 million in the first six months of 2024 compared to the same period of 2023. This was primarily due to changes in presentation driven by modification of agreements and increased costs from MPC, primarily higher employee costs.

Depreciation and amortization increased $31 million in the first six months of 2024 compared to the same period of 2023. This was primarily due to incremental depreciation associated with assets acquired in conjunction with the Torñado Acquisition in December 2023 and the Utica Midstream Acquisition in the first quarter of 2024, as well as other assets placed in service subsequent to the second quarter of 2023.

General and administrative expenses increased $38 million in the first six months of 2024 compared to the same period of 2023, due to increased contractor services costs and higher employee costs from MPC.

Segment Results

We classify our business in the following reportable segments: L&S and G&P. We evaluate the performance of our segments using Segment Adjusted EBITDA. Segment Adjusted EBITDA represents Adjusted EBITDA attributable to the reportable segments. Amounts included in net income and excluded from Segment Adjusted EBITDA include: (i) depreciation and amortization; (ii) net interest and other financial costs; (iii) income/(loss) from equity method investments; (iv) distributions and adjustments related to equity method investments; (v) impairment expense; (vi) noncontrolling interests; and (vii) other adjustments, as applicable. These items are either: (i) believed to be non-recurring in nature; (ii) not believed to be allocable or controlled by the segment; or (iii) are not tied to the operational performance of the segment.

The tables below present information about Segment Adjusted EBITDA for the reported segments for the three and six months ended June 30, 2024 and June 30, 2023.

L&S Segment

Second Quarter L&S Segment Financial Highlights (in millions)

(1) The six months ended June 30, 2024 includes a contribution of $92 million to a joint venture (“Dakota Access”) that owns and operates the Dakota Access Pipeline and Energy Transfer Crude Oil Pipeline projects (collectively the “Bakken Pipeline system”) to fund our share of a debt repayment by the joint venture.

Three months ended June 30, 2024 compared to three months ended June 30, 2023

Service revenue increased $82 million in the second quarter of 2024 compared to the same period of 2023. This was primarily driven by $51 million of higher pipeline tariff rates, as well as other fee escalations and higher pipeline throughput.

Income from equity method investments increased $178 million in the second quarter of 2024 compared to the same period of 2023. This was primarily driven by a $151 million gain related to the dilution of our ownership interest in connection with the Whistler Joint Venture Transaction, as well as increased throughput on equity method investment pipeline systems.

Other income increased $12 million in the second quarter of 2024 compared to the same period of 2023. This was primarily due to changes in presentation driven by modification of an agreement with MPC in the first quarter of 2024.

Purchases - related parties increased $19 million in the second quarter of 2024 compared to the same period of 2023, primarily due to changes in presentation driven by modification of agreements with MPC.

Six months ended June 30, 2024 compared to six months ended June 30, 2023

Service revenue increased $116 million in the first six months of 2024 compared to the same period of 2023. This was primarily driven by $109 million of higher pipeline tariff rates and other fee escalations, partially offset by a $16 million decrease related to lower pipeline throughput.

Rental income increased $21 million in the first six months of 2024 compared to the same period of 2023. This was primarily driven by fee escalations related to our refining logistics assets.

Income from equity methods investments increased $196 million in the first six months of 2024 compared to the same period of 2023. This was primarily driven by a $151 million gain related to the dilution of our ownership interest in connection with the Whistler Joint Venture Transaction, as well as increased throughput on equity method investment pipeline systems.

Other income increased $48 million in the first six months of 2024 compared to the same period of 2023. This was primarily due to business interruption insurance proceeds and changes in presentation driven by modification of an agreement with MPC in the first quarter of 2024.

Purchases - related parties increased $42 million in the first six months of 2024 compared to the same period of 2023. This was primarily due to changes in presentation driven by modification of agreements with MPC and increased costs from MPC, primarily higher employee costs.

General and administrative expenses increased $27 million in the first six months of 2024 compared to the same period of 2023, primarily due to increased contractor services costs and higher employee costs, including those from MPC.

L&S Operating Data

(1) Average tariff rates calculated using pipeline transportation revenues divided by pipeline throughput barrels. Transportation revenues include tariff and other fees, which may vary by region and nature of services provided.

(2) Represents total at end of period.

G&P Segment

Second Quarter G&P Segment Financial Highlights (in millions)

Three months ended June 30, 2024 compared to three months ended June 30, 2023

Service revenue increased $45 million in the second quarter of 2024 compared to the same period of 2023. This was primarily due to $31 million of incremental revenues from the consolidation of Torñado in December 2023 and an increase of $15 million from the Utica Midstream Acquisition that was completed in the first quarter of 2024.

Product related revenue increased $51 million in the second quarter of 2024 compared to the same period of 2023. This was primarily due to higher NGL prices across all regions of $42 million and higher NGL sales volumes in the Rockies and Bakken of $30 million, partially offset by lower NGL sales volumes in the Southwest of $11 million.

Other income decreased $18 million in the second quarter of 2024 compared to the same period of 2023 primarily due to a gain on disposal of assets recognized in the second quarter of 2023.

Cost of revenues increased $32 million in the second quarter of 2024 compared to the same period of 2023. This increase is attributable to higher operating costs and repairs and maintenance costs in the Rockies and Southwest of $28 million in addition to an increase of $10 million as a result of the consolidation of Torñado in December 2023. The increase was partially offset by lower operating costs and repairs and maintenance costs in the Marcellus during the second quarter of 2024.

Purchased product costs increased $22 million in the second quarter of 2024 compared to the same period of 2023. This was primarily due to higher NGL prices in the Southwest of $34 million partially offset by lower NGL volumes in the Southwest of $15 million.

Purchases - related parties increased $12 million in the second quarter of 2024 compared to the same period of 2023. The increase is attributable to higher transportation costs in the Southwest.

Depreciation and amortization increased $19 million in the second quarter of 2024 compared to the same period of 2023. This was primarily due to incremental depreciation associated with assets acquired in conjunction with the Torñado Acquisition in December 2023 and the Utica Midstream Acquisition in the first quarter of 2024, as well as other assets placed in service subsequent to the second quarter of 2023.

Six months ended June 30, 2024 compared to six months ended June 30, 2023

Service revenue increased $97 million in the first six months of 2024 compared to the same period of 2023. This was primarily due to $54 million of incremental revenues from the consolidation of Torñado in December 2023 and an increase of $15 million from the Utica Midstream Acquisition that was completed in the first quarter of 2024, as well as higher volumes and higher throughput fee rates across the Marcellus, Rockies and Bakken of $58 million. The increases were partially offset by lower volumes in the Southwest.

Product related revenue increased $10 million in the first six months of 2024 compared to the same period of 2023. This was primarily due to higher NGL sales volumes in the Rockies and Bakken of $56 million, partially offset by lower NGL sales volumes in the Southwest of $31 million, lower NGL prices across all regions and changes in the fair value of our propane contracts of $12 million.

Income from equity method investments increased $7 million in the first six months of 2024 compared to the same period of 2023. This was primarily due to higher volumes and higher throughput fee rates in the Utica and Marcellus of $20 million in addition to incremental income from the Utica Midstream Acquisition that was completed in the first quarter of 2024, partially offset by a $19 million decrease from the consolidation of Torñado in December 2023.

Cost of revenues increased $85 million in the first six months of 2024 compared to the same period of 2023. This increase is primarily attributable to higher operating costs and repairs and maintenance costs in the Marcellus, Rockies and Southwest of $64 million in addition to an increase of $24 million as a result of the consolidation of Torñado in December 2023.

Purchased product costs decreased $15 million in the first six months of 2024 compared to the same period of 2023. This was primarily due to lower NGL volumes in the Southwest of $36 million partially offset by higher NGL prices in the Southwest of $16 million.

Purchases - related parties was flat in the first six months of 2024 compared to the same period of 2023. Lower pricing in the Rockies was offset by higher transportation costs in the Southwest and increased employee costs from MPC.

Depreciation and amortization increased $39 million in the first six months of 2024 compared to the same period of 2023. This was primarily due to incremental depreciation associated with assets acquired in conjunction with the Torñado Acquisition in December 2023 and the Utica Midstream Acquisition in the first quarter of 2024, as well as other assets placed in service subsequent to the second quarter of 2023.

G&P Operating Data

(1) Other includes Southern Appalachia, Bakken and Rockies Operations.

(1) This column represents operating data for entities that have been consolidated into the MPLX financial statements.

(2) This column represents operating data for entities that have been consolidated into the MPLX financial statements as well as operating data for MPLX-operated equity method investments.

(3) Entities within the Marcellus and Utica Operations jointly own the Hopedale fractionation complex. Hopedale throughput is included in the Marcellus and Utica Operations and represents each region’s utilization of the complex.

(4) Purity ethane makes up approximately 272 mbpd and 226 mbpd of MPLX LP consolidated total fractionated products for the three months ended June 30, 2024 and June 30, 2023, respectively, and approximately 264 mbpd and 236 mbpd of total fractionated products for the six months ended June 30, 2024 and June 30, 2023, respectively. Purity ethane makes up approximately 293 mbpd and 232 mbpd of MPLX LP Operated total fractionated products for the three months ended June 30, 2024 and June 30, 2023, respectively, and approximately 278 mbpd and 242 mbpd of total fractionated products for the six months ended June 30, 2024 and June 30, 2023, respectively.

(1) C2 + NGL pricing based on Mont Belvieu prices assuming an NGL barrel of approximately 35 percent ethane, 35 percent propane, six percent Iso-Butane, 12 percent normal butane and 12 percent natural gasoline.

Seasonality

The volume of crude oil and refined products transported and stored utilizing our assets is affected by the level of supply and demand for crude oil and refined products in the markets served directly or indirectly by our assets. The majority of effects of seasonality on the L&S segment’s revenues are mitigated through the use of capacity-based agreements and minimum volume commitments.

In our G&P segment, we experience minimal impacts from seasonal fluctuations, which impact the demand for natural gas and NGLs and the related commodity prices caused by various factors including variations in weather patterns from year to year. Overall, our exposure to the seasonality fluctuations is limited due to the nature of our fee-based business.

Liquidity and Capital Resources

Cash Flows

Our cash and cash equivalents were $2,501 million at June 30, 2024 and $1,048 million at December 31, 2023. The change in cash and cash equivalents was due to the factors discussed below. Net cash provided by (used in) operating activities, investing activities and financing activities were as follows:

Net cash provided by operating activities increased $192 million in the first six months of 2024 compared to the same period of 2023, primarily due to improved results from operations during the first six months of 2024 compared to the same period of 2023.

Net cash used in investing activities increased $619 million in the first six months of 2024 compared to the same period of 2023, primarily due to the Utica Midstream Acquisition in the first quarter of 2024, as well as higher capital spending. The first six months of 2024 also reflects higher contributions to equity method investments, including a $92 million contribution to Dakota Access to fund our share of a scheduled debt repayment by the joint venture. The increases were partially offset by a $134 million cash distribution received, recorded as a return of capital, in connection with the Whistler Joint Venture Transaction.

Net cash used in financing activities decreased $1,363 million in the first six months of 2024 compared to the same period of 2023. The decrease was primarily due to proceeds from the issuance of $1.65 billion aggregate principal amount of 2034 Senior Notes during the first six months of 2024. This decrease was partially offset by the return of capital to unitholders through the unit repurchase program, as well as higher distributions paid to unitholders of $130 million during the first six months of 2024 compared to the same period of 2023, as a result of the 10 percent increase in our base distribution effective for the third quarter of 2023.

Adjusted Free Cash Flow

The following table provides a reconciliation of Adjusted FCF and Adjusted FCF after distributions from net cash provided by operating activities for the three and six months ended June 30, 2024 and June 30, 2023.

(1) The three months ended June 30, 2024 and June 30, 2023 include working capital draws of $166 million and $156 million, respectively.

The six months ended June 30, 2024 and June 30, 2023 include working capital draws of $95 million and $123 million, respectively.

(2) The three and six months ended June 30, 2024 include the impact of a $134 million cash distribution received in connection with the Whistler Joint Venture Transaction. The six months ended June 30, 2024 includes the impact of $622 million, net of cash acquired, related to the Utica Midstream Acquisition and a contribution of $92 million to Dakota Access to fund our share of a debt repayment by the joint venture.

Debt and Liquidity Overview

On May 20, 2024, MPLX issued $1.65 billion aggregate principal amount of the 2034 Senior Notes in an underwritten public offering. The 2034 Senior Notes were offered at a price to the public of 98.778 percent of par, with interest payable semi-annually in arrears, commencing on December 1, 2024. MPLX intends to use the net proceeds from the issuance of the 2034 Senior Notes to repay, redeem, or otherwise retire some or all of (i) MPLX’s outstanding $1,149 million aggregate principal amount of 4.875 percent senior notes due December 2024, (ii) MarkWest’s outstanding $1 million aggregate principal amount of 4.875 percent senior notes due December 2024 and (iii) MPLX’s outstanding $500 million aggregate principal amount of 4.000 percent senior notes due February 2025, and in the interim may use such net proceeds for general partnership purposes.

Our intention is to maintain an investment-grade credit profile. As of June 30, 2024, the credit ratings on our senior unsecured debt were as follows:

Rating Agency Rating

Moody’s Baa2 (stable outlook)

Standard & Poor’s BBB (stable outlook)

Fitch BBB (stable outlook)

The ratings reflect the respective views of the rating agencies and should not be interpreted as a recommendation to buy, sell or hold our securities. Although it is our intention to maintain a credit profile that supports an investment grade rating, there is no assurance that these ratings will continue for any given period of time. The ratings may be revised or withdrawn entirely by the rating agencies if, in their respective judgments, circumstances so warrant. A rating from one rating agency should be evaluated independently of ratings from other rating agencies.

The agreements governing our debt obligations do not contain credit rating triggers that would result in the acceleration of interest, principal or other payments solely in the event that our credit ratings are downgraded. However, any downgrades in the credit ratings of our senior unsecured debt ratings to below investment grade ratings could, among other things, increase the applicable interest rates and other fees payable under the MPLX Credit Agreement and may limit our ability to obtain future financing, including refinancing existing indebtedness.

Our liquidity totaled $6.0 billion at June 30, 2024 consisting of:

We expect our ongoing sources of liquidity to include cash generated from operations and borrowings under our revolving credit facilities and access to capital markets. We believe that cash generated from these sources will be sufficient to meet our short-term and long-term funding requirements, including working capital requirements, capital expenditure requirements, contractual obligations, and quarterly cash distributions. Our material future obligations include interest on debt, payments of debt principal, purchase obligations including contracts to acquire plant, property and equipment, and our operating leases and service agreements. We may also, from time to time, repurchase our senior notes or preferred units in the open market, in tender offers, in privately negotiated transactions or otherwise in such volumes, at market prices and upon such other terms as we deem appropriate and execute unit repurchases under our unit repurchase program.

MPC manages our cash and cash equivalents on our behalf directly with third-party institutions as part of the treasury services that it provides to us under our omnibus agreement. From time to time, we may also utilize other sources of liquidity, including the formation of joint ventures or sales of non-strategic assets.

MPLX’s credit agreement (the “MPLX Credit Agreement”) matures in July 2027 and contains certain representations and warranties, affirmative and restrictive covenants and events of default that we consider to be usual and customary for an agreement of this type. As of June 30, 2024, we were in compliance with such covenants.

MPLX is party to a loan agreement with MPC (the “MPC Loan Agreement”), which was renewed on July 31, 2024. The MPC Loan Agreement is now scheduled to expire, and borrowings under the loan agreement are scheduled to mature and become due and payable, on July 31, 2029, provided that MPC may demand payment of all or any portion of the outstanding principal amount of the loan, together with all accrued and unpaid interest and other amounts (if any), at any time prior to maturity.

Equity and Preferred Units Overview

Unit Repurchase Program

On August 2, 2022, we announced the board authorization for the repurchase of up to $1.0 billion of MPLX common units held by the public. The authorization has no expiration date. We may utilize various methods to effect the repurchases, which could include open market repurchases, negotiated block transactions, accelerated unit repurchases, tender offers or open market solicitations for units, some of which may be effected through Rule 10b5-1 plans. The timing and amount of future repurchases, if any, will depend upon several factors, including market and business conditions, and such repurchases may be suspended, discontinued, or restarted at any time.

Total unit repurchases were as follows for the respective periods:

(1) Cash paid for common units repurchased and average cost per unit includes commissions paid to brokers during the period.

As of June 30, 2024, we had $696 million remaining under the unit repurchase authorization.

Series A Redeemable Preferred Unit Conversions

During the three and six months ended June 30, 2024, certain Series A preferred unitholders exercised their rights to convert their Series A preferred units into approximately 11 million common units and 21 million common units, respectively. Approximately 6 million Series A preferred units remain outstanding as of June 30, 2024.

Distributions

On July 30, 2024, MPLX declared a cash distribution for the second quarter of 2024, totaling $868 million, or $0.850 per common unit. This distribution will be paid on August 16, 2024 to common unitholders of record on August 9, 2024. Although our partnership agreement requires that we distribute all of our available cash (as defined in the partnership agreement) each quarter, we do not otherwise have a legal obligation to distribute any particular amount per common unit. This rate will also be received by Series A preferred unitholders.

The allocation of total cash distributions is as follows for the three and six months ended June 30, 2024 and June 30, 2023. MPLX’s distributions are declared subsequent to quarter end; therefore, the following table represents total cash distributions applicable to the period in which the distributions were earned.

(1) The six months ended June 30, 2023 includes the portion of the $21 million distribution paid to the Series B preferred unitholders on February 15, 2023 that was earned during the period prior to redemption.

Capital Expenditures

Our operations are capital intensive, requiring investments to expand, upgrade, enhance or maintain existing operations and to meet environmental and operational regulations. Our capital requirements consist of growth capital expenditures and maintenance capital expenditures. Growth capital expenditures are those incurred for acquisitions or capital improvements that we expect will increase our operating capacity for volumes gathered, processed, transported or fractionated, decrease operating expenses within our facilities or increase operating income over the long term. Examples of growth capital expenditures include costs to develop or acquire additional pipeline, terminal, processing or storage capacity. In general, growth capital includes costs that are expected to generate additional or new cash flow for MPLX. In contrast, maintenance capital expenditures are those made to replace partially or fully depreciated assets, to maintain the existing operating capacity of our assets and to extend their useful lives, or other capital expenditures that are incurred in maintaining existing system volumes and related cash flows.

MPLX’s initial capital investment plan for 2024 is $1.1 billion, net of reimbursements, which includes growth capital of $950 million and maintenance capital of $150 million. The capital outlook excludes a $92 million equity method investment contribution made in March 2024 for the repayment of MPLX’s share of the Dakota Access joint venture’s debt, which reduced our maximum potential undiscounted payments under the Contingent Equity Contribution Agreement. Growth capital expenditures and investments in affiliates during the six months ended June 30, 2024 were primarily for gas processing plants in the Marcellus and Permian basins and gathering projects in the Marcellus, Utica and Permian basins. We continuously evaluate our capital plan and make changes as conditions warrant.

Our capital expenditures are shown in the table below:

(1) Total growth capital expenditures for the six months ended June 30, 2024 exclude $622 million of acquisitions, net of cash acquired, and a $134 million cash distribution received in connection with the Whistler Joint Venture Transaction.

(2) Investments in unconsolidated affiliates and additions to property, plant and equipment are shown as separate lines within investing activities in the Consolidated Statements of Cash Flows.

(3) Growth capital reimbursements are generally included in changes in deferred revenue within operating activities in the Consolidated Statements of Cash Flows. Maintenance capital reimbursements are included in the Contributions from MPC line within financing activities in the Consolidated Statements of Cash Flows.

Contractual Cash Obligations

As of June 30, 2024, our contractual cash obligations included debt, finance and operating lease obligations, purchase obligations for services and to acquire property, plant and equipment, and other liabilities. During the six months ended June 30, 2024, our debt obligations increased due to the issuance of the $1.65 billion aggregate principal amount of 2034 Senior Notes, described in Liquidity and Capital Resources - Debt and Liquidity Overview. There were no other material changes to our contractual obligations outside the ordinary course of business.

Off-Balance Sheet Arrangements

Off-balance sheet arrangements comprise those arrangements that may potentially impact our liquidity, capital resources and results of operations, even though such arrangements are not recorded as liabilities under GAAP. Our off-balance sheet arrangements are limited to guarantees that are described in Note 16 of the unaudited consolidated financial statements and indemnities as disclosed in our Annual Report on Form 10-K for the year ended December 31, 2023.

Although these arrangements serve a variety of our business purposes, we are not dependent on them to maintain our liquidity and capital resources, and we are not aware of any circumstances that are reasonably likely to cause the off-balance sheet arrangements to have a material adverse effect on our liquidity and capital resources.

Transactions with Related Parties

As of June 30, 2024, MPC owned our general partner and an approximate 63 percent limited partner interest in us. We perform a variety of services for MPC related to the transportation of crude and refined products, including renewables, via pipeline or marine, as well as terminal services, storage services and fuels distribution and marketing services, among others. The services that we provide may be based on regulated tariff rates or on contracted rates. In addition, MPC performs certain services for us related to information technology, engineering, legal, accounting, treasury, human resources and other administrative services.

The below table shows the percentage of Total revenues and other income as well as Total costs and expenses with MPC:

(1) 2024 periods exclude gain on dilution of ownership interest related to the Whistler Joint Venture Transaction.

For further discussion of agreements and activity with MPC and related parties see Item 1. Business in our Annual Report on Form 10-K for the year ended December 31, 2023 and Note 5 to the unaudited consolidated financial statements.

Environmental Matters and Compliance Costs

We have incurred and may continue to incur substantial capital, operating and maintenance, and remediation expenditures as a result of environmental laws and regulations. If these expenditures, as with all costs, are not ultimately reflected in the prices of our products and services, our operating results will be adversely affected. We believe that substantially all of our competitors must comply with similar environmental laws and regulations. However, the specific impact on each competitor may vary depending on a number of factors, including, but not limited to, the age and location of its operating facilities.

As previously disclosed in our Annual Report on Form 10-K for the year ended December 31, 2023, actual expenditures may vary as the number and scope of environmental projects are revised as a result of improved technology or changes in regulatory requirements. There have been no material changes to our environmental matters and compliance costs since our Annual Report on Form 10-K for the year ended December 31, 2023.

Critical Accounting Estimates

As of June 30, 2024, there have been no significant changes to our critical accounting estimates since our Annual Report on Form 10-K for the year ended December 31, 2023.

Accounting Standards Not Yet Adopted

As discussed in Note 2 to the unaudited consolidated financial statements, certain new financial accounting pronouncements will be effective for our financial statements in the future.

Item 3. Quantitative and Qualitative Disclosures about Market Risk

We are exposed to market risks related to the volatility of commodity prices. We employ various strategies, including the potential use of commodity derivative instruments, to economically hedge the risks related to these price fluctuations. We are also exposed to market risks related to changes in interest rates. As of June 30, 2024, we did not have any open financial or commodity derivative instruments to hedge the economic risks related to interest rate fluctuations; however, we continually monitor the market and our exposure and may enter into these arrangements in the future.

Commodity Price Risk

The information about commodity price risk for the three and six months ended June 30, 2024 does not differ materially from that discussed in Item 7A. Quantitative and Qualitative Disclosures about Market Risk of our Annual Report on Form 10-K for the year ended December 31, 2023.

Outstanding Derivative Contracts

See Notes 10 and 11 to the unaudited consolidated financial statements for more information about the fair value measurement of our derivative instruments, as well as the amounts recorded in our consolidated balance sheets and statements of income. We do not designate any of our commodity derivative instruments as hedges for accounting purposes.

Interest Rate Risk and Sensitivity Analysis

Sensitivity analysis of the effect of a hypothetical 100-basis-point change in interest rates on outstanding third-party debt, excluding finance leases, is provided in the following table. Fair value of cash and cash equivalents, receivables, accounts payable and accrued interest approximate carrying value and are relatively insensitive to changes in interest rates due to the short-term maturity of the instruments. Accordingly, these instruments are excluded from the table.

(1) Fair value was based on market prices, where available, or current borrowing rates for financings with similar terms and maturities.

(2) Assumes a 100-basis-point decrease in the weighted average yield-to-maturity at June 30, 2024.

(3) Assumes a 100-basis-point change in interest rates. The change to income before income taxes was based on the weighted average balance of all outstanding variable-rate debt for the six months ended June 30, 2024.

(4) MPLX had no outstanding borrowings on the MPLX Credit Agreement as of June 30, 2024.

At June 30, 2024, our portfolio of third‑party debt consisted of fixed-rate instruments and outstanding borrowings, if any, under the MPLX Credit Agreement. The fair value of our fixed-rate debt is relatively sensitive to interest rate fluctuations. Our sensitivity to interest rate declines and corresponding increases in the fair value of our debt portfolio unfavorably affects our results of operations and cash flows only when we elect to repurchase or otherwise retire fixed-rate debt at prices above carrying value. Interest rate fluctuations generally do not impact the fair value of borrowings under our MPLX Credit Agreement, but may affect our results of operations and cash flows.

See Note 10 in the unaudited consolidated financial statements for additional information on the fair value of our debt.

Item 4. Controls and Procedures

Disclosure Controls and Procedures

An evaluation of the effectiveness of the design and operation of our disclosure controls and procedures (as defined in Rules 13a-15(e) and 15d-15(e) under the Securities Exchange Act of 1934, as amended (the “Exchange Act”)) was carried out under the supervision and with the participation of our management, including the chief executive officer and chief financial officer of our general partner. Based upon that evaluation, the chief executive officer and chief financial officer of our general partner concluded that the design and operation of these disclosure controls and procedures were effective as of June 30, 2024, the end of the period covered by this Quarterly Report on Form 10-Q.

Changes in Internal Control over Financial Reporting

During the quarter ended June 30, 2024, there were no changes in our internal control over financial reporting that have materially affected, or are reasonably likely to materially affect, our internal control over financial reporting.

PART II – OTHER INFORMATION

Item 1. Legal Proceedings

We are the subject of, or a party to, a number of pending or threatened legal actions, contingencies and commitments involving a variety of matters, including laws and regulations relating to the environment. While it is possible that an adverse result in one or more of the lawsuits or proceedings in which we are a defendant could be material to us, based upon current information and our experience as a defendant in other matters, we believe that these lawsuits and proceedings, individually or in the aggregate, will not have a material adverse effect on our consolidated results of operations, financial position or cash flows.

Item 103 of Regulation S-K promulgated by the SEC requires disclosure of certain environmental matters when a governmental authority is a party to the proceedings and such proceedings involve potential monetary sanctions, unless we reasonably believe that the matter will result in no monetary sanctions, or in monetary sanctions, exclusive of interest and costs, of less than a specified threshold. We use a threshold of $1 million for this purpose.

There have been no material changes to the legal matters previously disclosed in our Annual Report on Form 10-K for the year ended December 31, 2023.

Item 1A. Risk Factors

There have been no material changes from the risk factors previously disclosed in our Annual Report on Form 10-K for the year ended December 31, 2023.

Item 2. Unregistered Sales of Equity Securities and Use of Proceeds

The following table sets forth a summary of our purchases during the quarter ended June 30, 2024 of equity securities that are registered by MPLX pursuant to Section 12 of the Exchange Act.

(1) Amounts in this column reflect the weighted average price paid for units purchased under our unit repurchase authorization. The weighted average price includes any commissions paid to brokers during the relevant period.

(2) On August 2, 2022, we announced the board authorization for the repurchase of up to $1 billion of MPLX common units held by the public. This unit repurchase authorization has no expiration date.

(3) The maximum dollar value remaining has been reduced by the amount of any commissions paid to brokers during the relevant period.

Item 5. Other Information

On July 31, 2024, MPLX and MPC Investment LLC entered into a Second Amendment to the MPC Loan Agreement, which extended the maturity date of the MPC Loan Agreement from July 31, 2024 to July 31, 2029.

Except as provided above, the terms of the MPC Loan Agreement remain materially unchanged. The foregoing description of the Second Amendment is not complete and is qualified in its entirety by reference to the full text of the Second Amendment, which is filed herewith as Exhibit 10.2 to this Quarterly Report on Form 10-Q and incorporated by reference herein.

MPC Investment LLC is a wholly owned subsidiary of MPC and the sole member of our general partner. In addition to controlling our general partner, MPC owned approximately 63 percent of the outstanding MPLX common units as of June 30, 2024.

During the quarter ended June 30, 2024, no director or officer (as defined in Rule 16a-1(f) promulgated under the Exchange Act) of MPLX adopted or terminated a “Rule 10b5-1 trading arrangement” or “non-Rule 10b5-1 trading arrangement” (as each term is defined in Item 408 of Regulation S-K).

Item 6. Exhibits

Exhibit Number Exhibit Description Incorporated by Reference From / Form Incorporated by Reference From / Exhibit Incorporated by Reference From / Filing Date Incorporated by Reference From / SEC File No. Filed Herewith Furnished Herewith

3.1 Certificate of Limited Partnership of MPLX LP S-1 3.1 7/2/2012 333-182500 3.2 Amendment to the Certificate of Limited Partnership of MPLX LP S-1/A 3.2 10/9/2012 333-182500 3.3 Sixth Amended and Restated Agreement of Limited Partnership of MPLX LP, dated as of February 1, 2021 8-K 3.1 2/3/2021 001-35714 10.1 Eighth Amendment to the Terminal Services Agreement, dated as of April 16, 2024, by and between the MPLX LP and Marathon Petroleum Corporation subsidiaries party thereto X 10.2 Second Amendment dated as of July 31, 2024 to Amended and Restated Loan Agreement dated as of July 31, 2019 by and between MPLX LP and MPC Investment LLC X 31.1 Certification of Chief Executive Officer pursuant to Rule 13a-14 and 15d-14 under the Securities Exchange Act of 1934 X 31.2 Certification of Chief Financial Officer pursuant to Rule 13a-14 and 15d-14 under the Securities Exchange Act of 1934 X 32.1 Certification of Chief Executive Officer pursuant to 18 U.S.C. Section 1350 X 32.2 Certification of Chief Financial Officer pursuant to 18 U.S.C. Section 1350 X 101.INS XBRL Instance Document: The instance document does not appear in the interactive data file because its XBRL tags are embedded within the Inline XBRL document. 101.SCH Inline XBRL Taxonomy Extension Schema Document. X 101.CAL Inline XBRL Taxonomy Extension Calculation Linkbase Document. X 101.DEF Inline XBRL Taxonomy Extension Definition Linkbase Document. X 101.LAB Inline XBRL Taxonomy Extension Label Linkbase Document. X 101.PRE Inline XBRL Taxonomy Extension Presentation Linkbase Document. X (104) Cover Page Interactive Data File (formatted as Inline XBRL and contained in Exhibit 101).