##### Table of Contents

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 10-Q

[X] QUARTERLY REPORT PURSUANT TO
SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the quarterly period ended
September 30, 2009

OR

[ ]
TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the
transition period from  to

Commission File No. 333-113340-01

MEWBOURNE ENERGY PARTNERS 05-A, L.P.



|                                                         |  |  |  |                                        
|-------------------------------------------------------- |  |  |  | ---------------------------------------
|Delaware                                                 |  |  |  | 20-2306210                             
|(State or jurisdiction of incorporation or organization) |  |  |  | (I.R.S. Employer Identification Number)



|                                         |  |            |  | 
|---------------------------------------- |  | ---------- |  | 
|3901 South Broadway, Tyler, Texas        |  | 75701      |  | 
|(Address of principal executive offices) |  | (Zip code) |  | 

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



|                                                                                   |  |  |  | 
|---------------------------------------------------------------------------------- |  |  |  | 
|Not Applicable                                                                     |  |  |  | 
|(Former name, former address and former fiscal year, if changed since last report) |  |  |  | 

Indicate by check mark whether the registrant (1) has filed all reports required to be
filed by Section 13 of 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.

Yes [X]  No [  ]

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of
Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such
files).    Yes [  ]    No [  ]

Indicate by check mark whether the
registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company in Rule 12b-2 of the Exchange Act. (Check one):

|                        |  |                                                    |  |                           |  |     
|----------------------- |  | -------------------------------------------------- |  | ------------------------- |  | ----
|Large accelerated filer |  | [  ]                                               |  | Accelerated filer         |  | [  ]
|Non-accelerated filer   |  | [  ] (Do not check if a smaller reporting company) |  | Smaller reporting company |  | [X] 

Indicate by check mark if the registrant is a shell company (as defined in Rule 12b-2 of the
Exchange Act).    Yes [  ]    No [X]



---

##### Table of Contents

MEWBOURNE ENERGY PARTNERS 05-A, L.P.

INDEX



|                                                                                                               |  |         
|-------------------------------------------------------------------------------------------------------------- |  | --------
|Part 1 - Financial Information                                                                                 |  | Page No.
|                                                                                                               | 
|Item 1. Financial Statements                                                                                   |  |         
|                                                                                                               | 
|Condensed Balance Sheets -September 30, 2009 (Unaudited) and December 31, 2008                                 |  | 3       
|                                                                                                               | 
|Condensed Statements of Operations (Unaudited) -                                                               |  |         
|For the three months ended September 30, 2009 and 2008and the nine months ended September 
30, 2009 and 2008   |  | 4       
|                                                                                                               | 
|Condensed Statements of Cash Flows (Unaudited) - For the nine months ended September 30, 2009 and 2008         |  | 5       
|                                                                                                               | 
|Condensed Statement of Changes In Partners Capital (Unaudited) -For the nine months ended September 
30, 2009 |  | 6       
|                                                                                                               | 
|Notes to Condensed Financial Statements                                                                        |  | 7       
|                                                                                                               | 
|Item 2. Managements Discussion and Analysis of Financial Condition and Results of Operations                  |  | 9       
|                                                                                                               | 
|Item 3. Quantitative and Qualitative Disclosures about Market Risk                                             |  | 13      
|                                                                                                               | 
|Item 4. Disclosure Controls and Procedures                                                                     |  | 13      
|                                                                                                               | 
|Part II - Other Information                                                                                    |  |         
|                                                                                                               | 
|Item 1. Legal Proceedings                                                                                      |  | 14      
|                                                                                                               | 
|Item 6. Exhibits and Reports on Form 8-K                                                                       |  | 14      



2



---

##### Table of Contents

MEWBOURNE ENERGY PARTNERS 05-A, L.P.

Part I - Financial Information

Item 1.  Financial
Statements

CONDENSED BALANCE SHEETS

September 30, 2009 and December 31, 2008



|                                                                     |  |                    |             |   |                   |   |             |  
|-------------------------------------------------------------------- |  | ------------------ | ----------- | - | ----------------- | - | ----------- | -
|                                                                     |  | September 30, 2009 |             |   | December 31, 2008 |  
|                                                                     |  | (Unaudited)        |             |   |                   |  
|ASSETS                                                               |  |                    |             |   |                   |   |             |  
|                                                                     |  |                   
|Cash                                                                 |  | $                  | 7,756       |   |                   | $ | 21,686      |  
|Accounts receivable, affiliate                                       |  |                    | 437,809     |   |                   |   | 973,427     |  
|Accounts receivable, other                                           |  |                    | -           |   |                   |   | 27,758      |  
|                                                                     |  |                    |             |   |                   |   |             |  
|Total current assets                                                 |  |                    | 445,565     |   |                   |   | 1,022,871   |  
|                                                                     |  |                    |             |   |                   |   |             |  
|                                                                     |  |                   
|Oil and gas properties at cost, full-cost method                     |  |                    | 30,050,301  |   |                   |   | 29,997,729  |  
|Less accumulated depreciation, depletion, amortizationand impairment |  |                    | (23,706,458 | ) |                   |   | (18,071,095 | )
|                                                                     |  |                    |             |   |                   |   |             |  
|                                                                     |  |                    | 6,343,843   |   |                   |   | 11,926,634  |  
|                                                                     |  |                    |             |   |                   |   |             |  
|                                                                     |  |                   
|Total assets                                                         |  | $                  | 6,789,408   |   |                   | $ | 12,949,505  |  
|                                                                     |  |                    |             |   |                   |   |             |  
|                                                                     |  |                   
|LIABILITIES AND PARTNERS CAPITAL                                    |  |                    |             |   |                   |   |             |  
|                                                                     |  |                   
|Accounts payable, affiliate                                          |  | $                  | 164,885     |   |                   | $ | 378,675     |  
|                                                                     |  |                    |             |   |                   |   |             |  
|Total current liabilities                                            |  |                    | 164,885     |   |                   |   | 378,675     |  
|                                                                     |  |                    |             |   |                   |   |             |  
|                                                                     |  |                   
|Asset retirement obligation                                          |  |                    | 130,049     |   |                   |   | 120,932     |  
|                                                                     |  |                   
|Partners capital                                                    |  |                    | 6,494,474   |   |                   |   | 12,449,898  |  
|                                                                     |  |                    |             |   |                   |   |             |  
|                                                                     |  |                   
|Total liabilities and partners capital                              |  | $                  | 6,789,408   |   |                   | $ | 12,949,505  |  
|                                                                     |  |                    |             |   |                   |   |             |  



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



3



---

##### Table of Contents

MEWBOURNE ENERGY PARTNERS 05-A, L.P.

CONDENSED STATEMENTS OF OPERATIONS

For the three months ended September 30, 2009 and 2008 and

the nine months ended September 30, 2009 and 2008

(Unaudited)



|                                                                                      |  |                                 |         |                                |   |           |  |   |            |   |  |   |          
|------------------------------------------------------------------------------------- |  | ------------------------------- | ------- | ------------------------------ | - | --------- |  | - | ---------- | - |  | - | ---------
|                                                                                      |  | Three Months EndedSeptember 30, |         | Nine Months EndedSeptember 30,
|                                                                                      |  |                                 |         |                               
|                                                                                      |  | 2009                            |         | 2008                           |   | 2009      |  |   | 2008      
|Revenues and other income:                                                            |  |                                 |         |                                |   |           |  |   |            |   |  |   |          
|Oil sales                                                                             |  | $                               | 144,190 |                                | $ | 436,864   |  | $ | 324,679    |   |  | $ | 1,260,391
|Gas sales                                                                             |  |                                 | 557,185 |                                |   | 2,349,765 |  |   | 1,757,983  |   |  |   | 6,309,821
|Interest income                                                                       |  |                                 | 14      |                                |   | 288       |  |   | 162        |   |  |   | 1,014    
|                                                                                      |  |                                 |         |                                |   |           |  |   |            |   |  |   |          
|Total revenues and other income                                                       |  |                                 | 701,389 |                                |   | 2,786,917 |  |   | 2,082,824  |   |  |   | 7,571,226
|                                                                                      |  |                                 |         |                                |   |           |  |   |            |   |  |   |          
|                                                                                      |  |                                 |         |                               
|Expenses:                                                                             |  |                                 |         |                                |   |           |  |   |            |   |  |   |          
|Lease operating expense                                                               |  |                                 | 86,960  |                                |   | 122,627   |  |   | 272,492    |   |  |   | 392,299  
|Production taxes                                                                      |  |                                 | 48,714  |                                |   | 167,586   |  |   | 144,785    |   |  |   | 497,530  
|Administrative and general expense                                                    |  |                                 | 12,869  |                                |   | 96,762    |  |   | 134,678    |   |  |   | 278,814  
|Depreciation, depletion, and amortization                                             |  |                                 | 184,795 |                                |   | 488,028   |  |   | 674,400    |   |  |   | 1,288,520
|Cost ceiling write-down                                                               |  |                                 | -       |                                |   | -         |  |   | 4,960,963  |   |  |   | -        
|Asset retirement obligation accretion                                                 |  |                                 | 2,129   |                                |   | 2,763     |  |   | 6,630      |   |  |   | 6,883    
|                                                                                      |  |                                 |         |                                |   |           |  |   |            |   |  |   |          
|Total expenses                                                                        |  |                                 | 335,467 |                                |   | 877,766   |  |   | 6,193,948  |   |  |   | 2,464,046
|                                                                                      |  |                                 |         |                                |   |           |  |   |            |   |  |   |          
|                                                                                      |  |                                 |         |                               
|Net income (loss)                                                                     |  | $                               | 365,922 |                                | $ | 1,909,151 |  | $ | (4,111,124 | ) |  | $ | 5,107,180
|                                                                                      |  |                                 |         |                                |   |           |  |   |            |   |  |   |          
|                                                                                      |  |                                 |         |                               
|Basic and diluted net income (loss) perpartner interest(30,000 interests outstanding) |  | $                               | 12.20   |                                | $ | 63.64     |  | $ | (137.04    | ) |  | $ | 170.24   
|                                                                                      |  |                                 |         |                                |   |           |  |   |            |   |  |   |          



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



4



---

##### Table of Contents

MEWBOURNE ENERGY PARTNERS 05-A, L.P.

CONDENSED STATEMENTS OF CASH FLOWS

For the nine months ended September 30, 2009 and 2008

(Unaudited)



|                                                                                           |  |                                |            |   |      |   |            |  
|------------------------------------------------------------------------------------------ |  | ------------------------------ | ---------- | - | ---- | - | ---------- | -
|                                                                                           |  | Nine Months EndedSeptember 30, |           
|                                                                                           |  |                               
|                                                                                           |  | 2009                           |            |   | 2008 |  
|Cash flows from operating activities:                                                      |  |                                |            |   |      |   |            |  
|Net income (loss)                                                                          |  | $                              | (4,111,124 | ) |      | $ | 5,107,180  |  
|Adjustments to reconcile net income (loss) to net cashprovided by operating activities:    |  |                                |            |   |      |   |            |  
|Depreciation, depletion, and amortization                                                  |  |                                | 674,400    |   |      |   | 1,288,520  |  
|Cost ceiling write-down                                                                    |  |                                | 4,960,963  |   |      |   | -          |  
|Asset retirement obligation accretion                                                      |  |                                | 6,630      |   |      |   | 6,883      |  
|Changes in operating assets and liabilities:                                               |  |                                |            |   |      |   |            |  
|Accounts receivable, affiliate                                                             |  |                                | 535,618    |   |      |   | (346,721   | )
|Accounts receivable, other                                                                 |  |                                | 27,758     |   |      |   | -          |  
|Accounts payable, affiliate                                                                |  |                                | (213,790   | ) |      |   | (1,228,021 | )
|                                                                                           |  |                                |            |   |      |   |            |  
|Net cash provided by operating activities                                                  |  |                                | 1,880,455  |   |      |   | 4,827,841  |  
|                                                                                           |  |                                |            |   |      |   |            |  
|                                                                                           |  |                               
|Cash flows from investing activities:                                                      |  |                                |            |   |      |   |            |  
|Purchase and development of oil and gas properties                                         |  |                                | (50,085    | ) |      |   | (234,802   | )
|                                                                                           |  |                                |            |   |      |   |            |  
|Net cash used in investing activities                                                      |  |                                | (50,085    | ) |      |   | (234,802   | )
|                                                                                           |  |                                |            |   |      |   |            |  
|                                                                                           |  |                               
|Cash flows from financing activities:                                                      |  |                                |            |   |      |   |            |  
|Cash distributions to partners                                                             |  |                                | (1,844,300 | ) |      |   | (4,560,639 | )
|                                                                                           |  |                                |            |   |      |   |            |  
|Net cash used in financing activities                                                      |  |                                | (1,844,300 | ) |      |   | (4,560,639 | )
|                                                                                           |  |                                |            |   |      |   |            |  
|                                                                                           |  |                               
|Net increase (decrease) in cash                                                            |  |                                | (13,930    | ) |      |   | 32,400     |  
|                                                                                           |  |                               
|Cash, beginning of period                                                                  |  |                                | 21,686     |   |      |   | 2,596      |  
|                                                                                           |  |                                |            |   |      |   |            |  
|                                                                                           |  |                               
|Cash, end of period                                                                        |  | $                              | 7,756      |   |      | $ | 34,996     |  
|                                                                                           |  |                                |            |   |      |   |            |  
|                                                                                           |  |                               
|Supplemental Cash Flow Information:                                                        |  |                                |            |   |      |   |            |  
|Non-cash changes to oil & gas properties related toasset retirement obligation liabilities |  | $                              | 2,487      |   |      | $ | 1,705      |  
|                                                                                           |  |                                |            |   |      |   |            |  



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



5



---

##### Table of Contents

MEWBOURNE ENERGY PARTNERS 05-A, L.P.

CONDENSED STATEMENT OF CHANGES IN PARTNERS CAPITAL

For the nine months ended September 30, 2009

(Unaudited)



|                              |  |                   |            |  
|----------------------------- |  | ----------------- | ---------- | -
|                              |  | Partners Capital |           
|                              | 
|Balance at December 31, 2008  |  | $                 | 12,449,898 |  
|                              | 
|Cash distributions            |  |                   | (1,844,300 | )
|                              | 
|Net loss                      |  |                   | (4,111,124 | )
|                              |  |                   |            |  
|                              | 
|Balance at September 30, 2009 |  | $                 | 6,494,474  |  
|                              |  |                   |            |  



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



6



---

##### Table of Contents

MEWBOURNE ENERGY PARTNERS 05-A, L.P.

NOTES TO CONDENSED FINANCIAL STATEMENTS

(Unaudited)



|1. | Accounting Policies
|-- | -------------------

Reference is hereby made to the Registrants Annual Report on Form 10-K for 2008, 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 periods presented. The results of operations for the interim
periods are not necessarily indicative of the final results expected for the full year. We have evaluated the impact on these condensed financial statements of all subsequent events through November 16, 2009, the date the financial statements
were issued.



|2. | Accounting for Oil and Gas Producing Activities
|-- | -----------------------------------------------

Mewbourne Energy Partners 05-A, L.P. (the Registrant or the Partnership), a Delaware limited partnership, is engaged primarily in oil and gas development and production in Texas, Oklahoma,
and New Mexico, and was organized on February 14, 2005. The offering of limited and general partnership interests began June 1, 2005 as a part of an offering registered under the name Mewbourne Energy Partners 04-05 Drilling Program, (the
Program), and concluded July 29, 2005, with total investor contributions of $30,000,000 originally being sold to 1,128 subscribers of which $26,844,000 were sold to 998 subscribers as general partner interests and $3,156,000 were
sold to 130 subscribers as limited partner interests. During 2007, all general partner equity interests were converted to limited partner equity interests. In accordance with the laws of the State of Delaware, Mewbourne Development Corporation
(MD), a Delaware Corporation, has been appointed as the Partnerships managing general partner. MD has no significant equity interest in the Partnership.

The Partnership follows the full-cost method of accounting for its oil and gas activities. Under the full-cost method, all productive and non-productive 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 September 30, 2009 and 2008, all capitalized costs were subject to amortization. Proceeds from the sale or other disposition of properties are credited to the full cost pool. 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 quarterly 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. There was a cost ceiling write-down of $4,960,963 at March 31, 2009 but none at June 30, 2009 or
September 30, 2009. There were no cost ceiling write-downs during the nine months ended September 30, 2008.



7



---

##### Table of Contents

|3. | Asset Retirement Obligations
|-- | ----------------------------

The Partnership has recognized an estimated liability for future plugging and abandonment costs. The estimated liability is based on historical experience and estimated well life. The liability is discounted using the credit-adjusted
risk-free rate. Revisions to the liability could occur due to changes in well ownership interests, well plugging and abandonment costs or well useful lives, or if federal or state regulators enact new well restoration requirements. The Partnership
recognizes accretion expense in connection with the discounted liability over the remaining life of the well.

A reconciliation of the
Partnerships liability for well plugging and abandonment costs for the nine months ended September 30, 2009 and the year ended December 31, 2008 is as follows:



|                             |  |                    |         |                   |   |        
|---------------------------- |  | ------------------ | ------- | ----------------- | - | -------
|                             |  | September 30, 2009 |         | December 31, 2008
|Balance, beginning of period |  | $                  | 120,932 |                   | $ | 110,239
|Liabilities incurred         |  |                    | 2,487   |                   |   | 1,705  
|Accretion expense            |  |                    | 6,630   |                   |   | 8,988  
|                             |  |                    |         |                   |   |        
|                             |  |                   
|Balance, end of period       |  | $                  | 130,049 |                   | $ | 120,932
|                             |  |                    |         |                   |   |        



|4. | Related Party Transactions
|-- | --------------------------

In accordance with the laws of the State of Delaware, Mewbourne Development Corporation (MD), a Delaware Corporation, has been appointed as the Partnerships managing general partner. MD has no significant equity interest
in the Partnership. Mewbourne Oil Company (MOC) is operator of oil and gas properties owned by the Partnership. Mewbourne Holdings, Inc. is the parent of both MD and MOC. Substantially all transactions are with MD and MOC.

In the ordinary course of business, MOC will incur certain costs that will be passed on to owners of the well for which the costs were incurred. The
Partnership will receive their portion of these costs based upon their ownership in each well incurring the costs. These costs are referred to as operator charges and are standard and customary in the oil and gas industry. Operator charges include
recovery of gas marketing costs, fixed rate overhead, supervision, pumping, and equipment furnished by the operator. Services and operator charges are billed in accordance with the program and partnership agreements.

In consideration for services rendered by MD in managing the business of the Partnership, the Partnership during each of the initial three years of
the Partnership will pay to MD a management fee in the amount equal to .7% of the subscriptions by the investor partners to the Partnership. Effective January 1, 2006 the Partnership has elected to include the management fee as part of the full
cost pool pursuant to Rule 4-10(c)(2) of Regulation S-X.

In general, during any particular calendar year the total amount of
administrative expenses allocated to the Partnership by MOC shall not exceed the greater of (a) 3.5% of the Partnerships gross revenue from the sale of oil and natural gas production during each year (calculated without any deduction for
operating costs or other costs and expenses) or (b) the sum of $50,000 plus .25% of the capital contributions of limited and general partners.



8



---

##### Table of Contents

The Partnership participates in oil and gas activities through a Drilling Program Agreement (the
Program). The Partnership and MD are parties to the Program. The costs and revenues of the Program are allocated to MD and the Partnership as follows:



|                                                                                                      |  |             |  |     
|----------------------------------------------------------------------------------------------------- |  | ----------- |  | ----
|                                                                                                      |  | Partnership |  | MD  
|Revenues:                                                                                             |  |             |  |     
|Proceeds from disposition of depreciable and depletable properties                                    |  | 70%         |  | 30% 
|All other revenues                                                                                    |  | 70%         |  | 30% 
|Costs and expenses:                                                                                   |  |             |  |     
|Organization and offering costs (1)                                                                   |  | 0%          |  | 100%
|Lease acquisition costs (1)                                                                           |  | 0%          |  | 100%
|Tangible and intangible drilling costs (1)                                                            |  | 100%        |  | 0%  
|Operating costs, reporting and legal expenses, general andadministrative expenses and all other costs |  | 70%         |  | 30% 



|(1) | Pursuant to the Program, MD must contribute 100% of organization and offering costs and lease acquisition costs which should approximate 20% of total capital
costs. To the extent that organization and offering costs and lease acquisition costs are less than 20% of total capital costs, MD is responsible for tangible drilling costs until its share of the Programs total capital costs reaches
approximately 20%. The Partnerships financial statements reflect its respective proportionate interest in the Program.
|--- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

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

Liquidity and
Capital Resources

Mewbourne Energy Partners 05-A, L.P. was formed February 14, 2005. The offering of limited and general
partnership interests began June 1, 2005 and concluded July 29, 2005, with total investor contributions of $30,000,000. During 2007, all general partner equity interests were converted to limited partner equity interests.

Future capital requirements and operations will be conducted with available funds generated from oil and gas activities. No bank borrowing is
anticipated. The Partnership had net working capital of $280,680 at September 30, 2009.

During the nine months ended
September 30, 2009, the Partnership made cash distributions to the investor partners in the amount of $1,844,300 as compared to $4,560,639 for the nine months ended September 30, 2008. The Partnership expects that cash distributions will
continue during 2009 as additional oil and gas revenues are sufficient to produce cash flows from operations.

The sale of crude oil and
natural gas produced by the Partnership will be affected by a number of factors that 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.



9



---

##### Table of Contents

Results of Operations

For the three months ended September 30, 2009 as compared to the three months ended September 30, 2008:



|                  |  |                                  |         |      |   |          
|----------------- |  | -------------------------------- | ------- | ---- | - | ---------
|                  |  | Three Months Ended September 30,
|                  |  | 2009                             |         | 2008
|Oil sales         |  | $                                | 144,190 |      | $ | 436,864  
|Barrels produced  |  |                                  | 2,191   |      |   | 3,812    
|Average price/bbl |  | $                                | 65.81   |      | $ | 114.60   
|                  |  |                                 
|Gas sales         |  | $                                | 557,185 |      | $ | 2,349,765
|Mcf produced      |  |                                  | 164,470 |      |   | 262,290  
|Average price/mcf |  | $                                | 3.39    |      | $ | 8.96     

Oil and gas revenues. As shown in the above table, total oil and gas sales decreased by
$2,085,254, a 74.8 % decline, for the three months ended September 30, 2009 as compared to the three months ended September 30, 2008.

Of this decrease, $185,996 and $1,461,189 were due to decreases in the average prices of oil and gas sold, respectively. Average prices fell to $65.81 from $114.60 per bbl and to $3.39 from $8.96 per mcf for the
three months ended September 30, 2009 as compared to the three months ended September 30, 2008. In addition, $106,678 and $331,391 were due to decreases in the volumes of oil and gas sold by 1,621 bbls and 97,820 mcf. The decreases in
volumes of oil and gas sold were primarily due to normal declines in production. In some wells with variable production capacity the Partnership elected to decrease production during periods of lower prices.

Lease operations. Lease operating expense during the three month period ended September 30, 2009 decreased to $86,960 from $122,627 due to fewer
well repairs and workovers in the three month period ended September 30, 2009.

Production taxes. Production taxes during the three
month period ended September 30, 2009 decreased to $48,714 from $167,586 for the three month period ended September 30, 2008 due to lower revenue.

Administrative and general expense. Administrative and general expense for the three month period ended September 30, 2009 decreased to $12,869 from $96,762 for the three month period ended September 30,
2008. The overall decrease was due to decreased administrative expenses allocable to the Partnership for the three month period ended September 30, 2009 and lower general expenses and credits for reporting costs.

Depreciation, depletion and amortization. Depreciation, depletion and amortization for the three month period ended September 30, 2009 decreased
to $184,795 from $488,028 for the three month period ended September 30, 2008 due to a lower amortizable base at September 30, 2009. The reduced amortizable base was due to the March 31, 2009 cost ceiling write-down of $4,960,963.



10



---

##### Table of Contents

Results of Operations

For the nine months ended September 30, 2009 as compared to the nine months ended September 30, 2008:



|                  |  |                                 |           |      |   |          
|----------------- |  | ------------------------------- | --------- | ---- | - | ---------
|                  |  | Nine Months Ended September 30,
|                  |  | 2009                            |           | 2008
|Oil sales         |  | $                               | 324,679   |      | $ | 1,260,391
|Barrels produced  |  |                                 | 6,469     |      |   | 11,343   
|Average price/bbl |  | $                               | 50.19     |      | $ | 111.12   
|                  |  |                                
|Gas sales         |  | $                               | 1,757,983 |      | $ | 6,309,821
|Mcf produced      |  |                                 | 453,093   |      |   | 709,610  
|Average price/mcf |  | $                               | 3.88      |      | $ | 8.89     

Oil and gas revenues. As shown in the above table, total oil and gas sales decreased by
$5,487,550, a 72.5% decline, for the nine months ended September 30, 2009 as compared to the nine months ended September 30, 2008.

Of this decrease, $691,086 and $3,556,562 were due to decreases in the average prices of oil and gas sold, respectively. Average prices fell to $50.19 from $111.12 per bbl and to $3.88 from $8.89 per mcf for the nine months ended
September 30, 2009 as compared to the nine months ended September 30, 2008. In addition, $244,626 and $995,276 were due to decreases in the volumes of oil and gas sold by 4,874 bbls and 256,517 mcf. The decreases in volumes of oil and gas
sold were primarily due to normal declines in production and to the curtailment of some of the Partnerships wells during April, 2009 and May, 2009.

Lease operations. Lease operating expense during the nine month period ended September 30, 2009 decreased to $272,492 from $392,299 due to fewer well repairs and workovers in the nine month period ended
September 30, 2009.

Production taxes. Production taxes during the nine month period ended September 30, 2009 decreased to
$144,785 from $497,530 for the nine month period ended September 30, 2008 due to lower revenue.

Administrative and general
expense. Administrative and general expense for the nine month period ended September 30, 2009 decreased to $134,678 from $278,814 for the nine month period ended September 30, 2008. The overall decrease was due to decreased administrative
expenses allocable to the Partnership for the nine month period ended September 30, 2009 and lower general expenses and credits for reporting costs.

Depreciation, depletion and amortization. Depreciation, depletion and amortization for the nine month period ended September 30, 2009 decreased to $674,400 from $1,288,520 for the nine month period ended
September 30, 2008 due to a lower amortizable base at September 30, 2009. The reduced amortizable base was due to the March 31, 2009 cost ceiling write-down.

Cost ceiling write-down. There was a cost ceiling write-down of $4,960,963 at March 31, 2009 but none at June 30, 2009 or September 30, 2009. The write-down was the result of
lower oil and gas prices on that date. There were no cost ceiling write-downs during the nine months ended September 30, 2008.



11



---

##### Table of Contents

New Accounting Pronouncements

FASB Accounting Standards Codification and the Hierarchy of Generally Accepted Accounting Principles. In June 2009, the FASB issued guidance on the accounting standards codification and the hierarchy of generally
accepted accounting principles. The accounting standards codification is intended to be the source of authoritative US GAAP and reporting standards as issued by the Financial Accounting Standards Board (FASB). Its primary purpose is
to improve clarity and use of existing standards by grouping authoritative literature under common topics. This Statement is effective for financial statements issued for interim and annual periods ending after September 15, 2009. Effective
July 1, 2009, the Partnership will describe the authoritative guidance used within the footnotes but will cease using numerical references. The accounting standards codification does not change or alter existing US GAAP, and there is no
expected impact on the Partnerships financial position, results of operations or cash flows.

Interim Disclosures about Fair Value
of Financial Instruments. In April 2009, the FASB issued a staff position requiring fair value disclosures in both interim as well as annual financial statements in order to provide more timely information about the effects of current market
conditions on financial instruments. The guidance is effective for interim and annual periods ending after June 15, 2009. The implementation of this standard did not have a material impact on the Partnerships financial position and
results of operations.

Accounting for Transfers of Financial Assets. In June 2009, the FASB issued an amendment to the accounting and
disclosure requirements for transfers of financial assets. The guidance requires additional disclosures for transfers of financial assets and changes the requirements for derecognizing financial assets. The guidance is effective for fiscal years
beginning after November 15, 2009. The Partnership does not anticipate any impact of the guidance on its financial position and results of operations.

Modernization of Natural Gas and Oil Reporting. In January 2009, the SEC issued revisions to the natural gas and oil reporting disclosures, Modernization of Oil and Gas Reporting, Final Rule (the
Final Rule). In addition to changing the definition and disclosure requirements for natural gas and oil reserves, the Final Rule changes the requirements for determining quantities of natural gas and oil reserves. The Final Rule also
changes certain accounting requirements under the full cost method of accounting for natural gas and oil activities. The amendments are designed to modernize the requirements for the determination of natural gas and oil reserves, aligning them with
current practices and updating them for changes in technology. The Final Rule is effective for annual reports on Form10-K for fiscal years ending on or after December 31, 2009. The Partnership currently is assessing the impact of adoption but
does not expect that it will have a material impact on the Partnerships financial position, results of operations or cash flows.



12



---

##### Table of Contents

Item 3.    Quantitative and Qualitative Disclosures about Market Risk



|1. | Interest Rate Risk
|-- | ------------------

The
Partnership Agreement allows borrowings from banks or other financial sources of up to 20% of the total capital contributions to the Partnership without investor approval. Should the Partnership elect to borrow monies for additional development
activity on Partnership properties, it will be subject to the interest rate risk inherent in borrowing activities. Changes in interest rates could significantly affect the Partnerships results of operations and the amount of net cash flow
available for partner distributions. Also, to the extent that changes in interest rates affect general economic conditions, the Partnership will be affected by such changes.



|2. | Commodity Price Risk
|-- | --------------------

The
Partnership does not expect to engage in commodity futures trading or hedging activities or enter into derivative financial instrument transactions for trading or other speculative purposes. The Partnership currently expects to sell a
significant amount of its production from successful oil and gas wells on a month-to-month basis at market prices. Accordingly, the Partnership is at risk for the volatility in commodity prices inherent in the oil and gas industry, and the level of
commodity prices will have a significant impact on the Partnerships results of operations. For the nine months ended September 30, 2009, a 10% change in the price received for natural gas production would have had an approximate $176,000
impact on revenue.



|3. | Exchange Rate Risk
|-- | ------------------

The
Partnership currently has no income from foreign sources or operations in foreign countries that would subject it to currency exchange rate risk. The Partnership does not currently expect to purchase any prospects located outside of either the
United States or United States coastal waters in the Gulf of Mexico.

Item 4.    Disclosure Controls and Procedures

MD 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. MDs Chief
Executive Officer and Chief Financial Officer have evaluated the effectiveness of the design and operation of its disclosure controls and procedures with the assistance and participation of other members of management. Based upon that evaluation,
MDs Chief Executive Officer and Chief Financial Officer concluded that its 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. Since MDs December 31, 2008 annual report on internal control over financial reporting, and for the quarter ended
September 30, 2009, there have been no changes in MDs internal controls or in other factors which have materially affected, or are reasonably likely to materially affect, the internal controls over financial reporting.



13



---

##### Table of Contents

Part II - Other Information

Item 1.    Legal Proceedings

| |  | None.
| |  | -----

Item 6.    Exhibits and Reports on Form 8-K



| | (a) | Exhibits filed herewith.
| | --- | ------------------------



| | 31.1 | Certification of CEO Pursuant to Section 302 of
| | ---- | -----------------------------------------------

| |  | Sarbanes-Oxley Act of 2002.
| |  | ---------------------------



| | 31.2 | Certification of CFO Pursuant to Section 302 of
| | ---- | -----------------------------------------------

| |  | Sarbanes-Oxley Act of 2002.
| |  | ---------------------------



| | 32.1 | Certification of CEO Pursuant to Section 906 of
| | ---- | -----------------------------------------------

| |  | Sarbanes-Oxley Act of 2002.
| |  | ---------------------------



| | 32.2 | Certification of CFO Pursuant to Section 906 of
| | ---- | -----------------------------------------------

| |  | Sarbanes-Oxley Act of 2002.
| |  | ---------------------------



| | (b) | Reports on Form 8-K
| | --- | -------------------

| |  | None.
| |  | -----



14



---

##### Table of Contents

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.



Mewbourne Energy Partners 05-A, L.P.By:

Mewbourne Development Corporation Managing General
Partner


Date:
                    November 16, 2009



By:

/s/ Alan ClarkAlan Clark, Treasurer and Controller




15



---

##### Table of Contents

INDEX TO EXHIBITS



|              |  |                                                                            
|------------- |  | ---------------------------------------------------------------------------
|EXHIBITNUMBER |  | DESCRIPTION                                                                
|              | 
|31.1          |  | Certification of CEO Pursuant to Section 302 of Sarbanes-Oxley Act of 2002.
|              | 
|31.2          |  | Certification of CFO Pursuant to Section 302 of Sarbanes-Oxley Act of 2002.
|              | 
|32.1          |  | Certification of CEO Pursuant to Section 906 of Sarbanes-Oxley Act of 2002.
|              | 
|32.2          |  | Certification of CFO Pursuant to Section 906 of Sarbanes-Oxley Act of 2002.



16