UNITED STATES
SECURITIES AND EXCHANGE COMMISSION

FORM 10-Q

                     For the quarterly period ended March 31, 2004

or

                     For the transition period from            to            

Commission File No. 333-85994-01

MEWBOURNE ENERGY PARTNERS 03-A, L.P.

Registrant’s Telephone Number, including area code:(903) 561-2900

Not Applicable

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. [X] Yes [  ] No

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Mewbourne Energy Partners 03-A, L. P.

INDEX

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Mewbourne Energy Partners 03-A, L. P.

Part I — Financial Information

Item 1. Financial Statements

BALANCE SHEETS
March 31, 2004 and December 31, 2003

The accompanying notes are an integral
part of the financial statements.

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Mewbourne Energy Partners 03-A, L. P.

STATEMENTS OF OPERATIONS
For the three months ended March 31, 2004 and
the period from February 19, 2003 (date of inception)
through March 31, 2003
(Unaudited)

The accompanying notes are an integral
part of the financial statements.

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Mewbourne Energy Partners 03-A, L. P.

STATEMENTS OF CASH FLOWS
For the three months ended March 31, 2004 and
the period from February 19, 2003 (date of inception)
through March 31, 2003
(Unaudited)

The accompanying notes are an integral
part of the financial statements.

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Mewbourne Energy Partners 03-A, L. P.

STATEMENT OF CHANGES IN PARTNERS’ CAPITAL
For the three months ended March 31, 2004
(Unaudited)

The accompanying notes are an integral
part of the financial statements.

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Mewbourne Energy Partners 03-A, L.P.

NOTES TO FINANCIAL STATEMENTS
(Unaudited)

1. Accounting Policies

Reference is hereby made to the Partnership’s Annual Report on Form 10-K for 2003, which contains a summary of significant accounting policies followed by the partnership in the preparation of its financial statements. These policies are also followed in preparing the quarterly report included herein.

In the opinion of management, the accompanying unaudited financial statements contain all adjustments of a normal recurring nature necessary to present fairly our financial position, results of operations, cash flows and partners’ capital for the three months ended March 31, 2004. The results of operations for the three months ended March 31, 2004 are not necessarily indicative of the final results expected for the full year.

2. Accounting for Oil and Gas Producing Activities

Mewbourne Energy Partners 03-A, L.P., (the “Partnership”), a Delaware limited partnership formed on February 19, 2003, is engaged primarily in oil and gas development and production in Texas, Oklahoma, and New Mexico. The offering of limited and general partnership interests began May 16, 2003 as a part of an offering registered under the name Mewbourne Energy Partners 02-03 Drilling Programs and concluded July 9, 2003, with total investor contributions of $18,000,000. Since the partnership was not funded until July 9, 2003, no business was conducted by the Partnership during the period February 19, 2003 (date of inception) to March 31, 2003, therefore, there are no items of income or expense for that reporting period.

The Partnership follows the full-cost method of accounting for its oil and gas activities. Under the full-cost method, all productive and nonproductive costs incurred in the acquisition, exploration and development of oil and gas properties are capitalized. Depreciation, depletion and amortization of oil and gas properties subject to amortization is computed on the units-of-production method based on the proved reserves underlying the oil and gas properties. At March 31, 2004, approximately $0.8 million of capitalized costs were excluded from amortization, while at December 31, 2003, approximately $0.5 million of capitalized costs were excluded from amortization. Gains and losses on the sale or other disposition of properties are not recognized unless such adjustments would significantly alter the relationship between capitalized costs and the proved oil and gas reserves. Capitalized costs are subject to a periodic ceiling test that limits such costs to the aggregate of the present value of future net cash flows of proved reserves and the lower of cost or fair value of unproved properties.

3. Comprehensive Income

Total comprehensive income (loss) equals net income (loss) during each of the periods presented herein.

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4. Asset Retirement Obligations

In accordance with FAS 143, the Partnership has recognized an estimated liability for future oil and gas well plugging and abandonment costs. The estimated liability is based on historical experience and estimated well lives. The liability is discounted using the credit-adjusted risk-free rate. Revisions to the liability could occur due to changes in well plugging and abandonment costs or well useful lives, or if federal or state regulators enact new well restoration requirements.

A reconciliation of the Partnership’s liability for well plugging and abandonment costs for the three months ended March 31, 2004 and the period from February 19, 2003 (date of inception) through December 31, 2003, is as follows:

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

Liquidity and Capital Resources

Mewbourne Energy Partners 03-A, L.P. (the “Partnership”)was formed February 19, 2003. The offering of limited and general partnership interests began on May 16, 2003 and concluded on July 9, 2003, with investor partner contributions of $18,000,000.

The Partnership has acquired interests in oil and gas prospects for the purpose of development drilling. At March 31, 2004, 42 wells had been drilled and were productive and 7 wells were drilled and abandoned.

Operations will be conducted with available funds and revenues generated from oil and gas activities. No bank borrowing is anticipated. The Partnership had net working capital of $5,269,626 at March 31, 2004.

During the three months ended March 31, 2004, the Partnership made cash distributions to the investor partners in the amount of $635,000. The Partnership expects that cash distributions will continue during 2004 as additional oil and gas revenues are received.

The sale of crude oil and natural gas produced by the Partnership will be affected by a number of factors which are beyond the Partnership’s control. These factors include the price of crude oil and natural gas, the fluctuating supply of and demand for these products, competitive fuels, refining, transportation, extensive federal and state regulations governing the production and sale of crude oil and natural gas, and other competitive conditions. It is impossible to predict with any certainty the future effect of these factors on the Partnership.

Results of Operations

Revenues and other income during the period from January 1, 2004 to March 31, 2004 totaled $1,122,861, and consisted of oil and gas sales of $1,113,627 and interest income of $9,234. Production volumes during the period ended March 31, 2004 were approximately 3,553 bbls of oil and 195,366 mcf of gas at corresponding average realized prices of $33.60 per bbl of oil and $5.09 per mcf of gas. Expenses totaling $655,636, consisting primarily of lease operating expenses in the amount of $56,326, production taxes in the amount of $96,755, and depreciation, depletion, and amortization in the amount of $477,838 resulted in net income for the period of $467,225. The Partnership’s oil and gas production should increase during the remainder of 2004 as additional wells are completed and oil and gas production is sold. Interest income should decrease in 2004 as the available cash is utilized for drilling and equipping of wells. The Partnership expects that drilling and completion costs will decrease during 2004 and that production costs, operating expenses and depletion provisions will increase.

The Partnership’s operations did not commence until the third quarter of 2003. No corresponding activities, therefore, occurred during the period from February 19, 2003 (date of inception) through March 31, 2003.

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Asset Retirement Obligation

In accordance with FAS 143, the Partnership has recognized an estimated liability for future oil and gas well plugging and abandonment costs (see Note 4). The estimated liability is based on historical experience and estimated well lives. The liability is discounted using the credit-adjusted risk-free rate. Revisions to the liability could occur due to changes in well plugging and abandonment costs or well useful lives, or if federal or state regulators enact new well restoration requirements.

A reconciliation of the Partnership’s liability for well plugging and abandonment costs for the three months ended March 31, 2004 and the period from February 19, 2003 (date of inception) through December 31, 2003, is as follows:

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Item 4. Disclosure Controls and Procedures

Mewbourne Development Corporation (“MDC”), the Managing General Partner of the Partnership, maintains a system of controls and procedures designed to provide reasonable assurance as to the reliability of the financial statements and other disclosures included in this report, as well as to safeguard assets from unauthorized use or disposition. Within 90 days prior to the filing of this report, MDC’s Chief Executive Officer and Chief Financial Officer have evaluated the effectiveness of the design and operation of our disclosure controls and procedures with the assistance and participation of other members of management. Based upon that evaluation, MDC’s Chief Executive Officer and Chief Financial Officer concluded that our disclosure controls and procedures are effective for gathering, analyzing and disclosing the information the Partnership is required to disclose in the reports it files under the Securities Exchange Act of 1934 within the time periods specified in the SEC’s rules and forms. There have been no significant changes in MDC’s internal controls or in other factors which could significantly affect internal controls subsequent to the date MDC carried out its evaluation.

Part II — Other Information

Item 1. Legal Proceedings

1. Faulconer Resources 2000, LP, et al. v. Mewbourne Oil Company; No. CV-2004-56 JWF; In the Fifth Judicial District Court, Eddy County New Mexico

Plaintiffs Faulconer filed suit February 13, 2004 for Declaratory Judgment, Tortuous Interference with Leasehold Interest, Temporary Restraining Order and Preliminary Injunction, seeking direct and consequential damages for breach of duties, attorneys fees and punitive damages for tortuous interference with malice. Plaintiffs seek an injunction to deny Mewbourne Oil Company (“MOC”) the opportunity to drill its La Huerta “30” Fee Com. No. 1 well, in which the partnership owns a working interest.

Plaintiffs claim that MOC has no right to cause the wellbore of the La Huerta well to traverse the underground rock strata in the SE/4 of Section 19 and the NE/4 of Section 30 on its way to a bottom hole location in the SE/4 of Section 30, all in Township 21 South, Range 27 East, Eddy County, New Mexico. Plaintiffs own no interest in the SE/4 of Section 30, but do own oil and gas leasehold interests in the SE/4 of Section 19 and the NE/4 of Section 30, subject to a current Farmout Agreement with MOC as Farmee and Plaintiffs as Farmor. Plaintiffs claim the right to exclude MOC’s La Huerta’s wellbore from proceeding through the underground rock strata where Plaintiffs own oil and gas leasehold interests. Plaintiffs assert MOC’s wellbore would constitute a permanent trespass, causing Plaintiffs irreparable injury and seek to enjoin the drilling of the well. Plaintiffs claim MOC’s filing of an application to drill the well with regulatory bodies constitutes a deliberate and malicious interference with the contractual relationships between Plaintiffs and their lessors.

MOC believes it has the right to drill its La Huerta well as planned. The bottom hole location for the well is within a residential area nearby the city of Carlsbad, New Mexico. A surface location for the well within the SE/4 of Section 30 is not feasible or appropriate due to the proximity of residences and the inability to construct and use a natural gas pipeline to gather and transport natural gas produced by the well. Thus, MOC proposes to drill a deviated well from a surface location within the SE/4 of Section 19, for which MOC has acquired a surface use easement and agreement. The wellbore would traverse the SE/4 of Section 19 and the NE/4 of Section 30 before

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entering MOC’s leasehold area in the S/2 of Section 30. After MOC notified Plaintiffs of MOC’s plans, Plaintiffs asserted that MOC did not have authority to execute its plans without Plaintiffs consent and sued MOC. Plaintiffs have refused to consent to MOC’s plans unless MOC gives Plaintiffs a substantial working interest in the La Huerta well.

     Plaintiff’s’ presented their application for preliminary injunction to the court on March 3, 2004. MOC vigorously contested Plaintiffs’ claims. MOC believes that Plaintiffs should not be permitted to block the drilling of the La Huerta well unless Plaintiffs can show that their leasehold rights in the SE/4 of Section 19 and the NE/4 of Section 30 would be interfered with unreasonably by MOC’s well. MOC further believes Plaintiffs failed to prove such unreasonable interference would occur as a result of the drilling of the La Huerta well. By Order dated March 17, 2004, the court denied Plaintiffs’ application for injunctive relief, finding that MOC would not be trespassing upon Plaintiffs’ oil and gas leasehold estates, that MOC’s operations would not interfere with operation of Plaintiffs’ oil and gas leasehold interests, either surface or subsurface and that Plaintiffs would not suffer irreparable damage in any respect. Plaintiffs have advised MOC that they will appeal the Court’s ruling. MOC does not believe the Court’s order will be reversed on appeal. Accordingly, MOC has commenced drilling operations on the La Huerta “30” No. 1-Y well in keeping with the Court’s order and to prevent drainage and protect its correlative rights.

Item 6. Exhibits and Reports on Form 8-K

     (a) Exhibits filed herewith.

     (b) Reports on Form 8-K — none

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SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the Partnership has duly caused this report to be signed on its behalf by the undersigned thereto duly authorized.

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INDEX TO EXHIBITS

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