| OMB      APPROVAL                                                                                                                      |
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| OMB      Number:  3235-0058Expires:       April 30, 2009Estimated      average burdenhours      per response  2.50 |
| SEC      FILE NUMBER000-51309                                                                                                          |

| (Check      one): |   |       Form 10-K    Form 20-F         Form 11-K   x Form 10-Q         Form 10-D         Form N-SAR         Form N-CSR |
|-------------------|--------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|

|   |   | For      Period Ended: September 30,      2008                                                                                                                                        |
|--------|--------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
|   |   |                                                                                                                                                                                                                                                                                                                                     |   | Transition      Report on Form 10-K |
|   |   |                                                                                                                                                                                                                                                                                                                                     |   | Transition      Report on Form 20-F |
|   |   |                                                                                                                                                                                                                                                                                                                                     |   | Transition      Report on Form 11-K |
|   |   |                                                                                                                                                                                                                                                                                                                                     |   | Transition      Report on Form 10-Q |
|   |   |                                                                                                                                                                                                                                                                                                                                     |   | Transition      Report on Form N-SAR |
|   |   | For      the Transition Period Ended:                                                  |

| Read      Instruction (on back page) Before Preparing Form. Please Print or      TypeNothing      in this form shall be construed to imply that the Commission has verified      any information contained herein. |
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| If      the notification relates to a portion of the filing checked above,      identify the Item(s) to which the notification relates: |
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| PART I — REGISTRANT      INFORMATION                                                                                              |
| PDC      2005-A Limited Partnership                                                                                                     |
| Full      Name of Registrant                                                                                                            |
|                                                                                                                                    |
| Former      Name if Applicable                                                                                                          |
|                                                                                                                                    |
| 120      Genesis Blvd                                                                                                                   |
| Address      of Principal Executive Office (Street and      Number)                                                                     |
|                                                                                                                                    |
| Bridgeport,      WV 26330                                                                                                               |
| City,      State and Zip Code                                                                                                           |

|   |   |   |   |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
|--------|--------|--------|--------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
|   |   | (a)    |   | The      reason described in reasonable detail in Part III of this form could not      be eliminated without unreasonable effort or expense                                                                                                                                                                                                                                                                                                                                                                                                          |
|   |   | (b)    |   | The      subject annual report, semi-annual report, transition report on      Form 10-K, Form 20-F, Form 11-K, Form N-SAR or      Form N-CSR, or portion thereof, will be filed on or before the      fifteenth calendar day following the prescribed due date; or the subject      quarterly report or transition report on Form 10-Q, or subject      distribution report on Form 10-D, or  portion thereof, will be      filed on or before the fifth calendar day following the prescribed due      date; and |
|   |   | (c)    |   | The      accountant’s statement or other exhibit required by Rule 12b-25(c)      has been attached if applicable.                                                                                                                                                                                                                                                                                                                                                                                                                         |

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|            |                                                                                    |
|-----------------|-----------------------------------------------------------------------------------------|
| (1)   | Name      and telephone number of person to contact in regard to this      notification |

| Darwin      L. StumpChief      Accounting OfficerPetroleum      Development Corporation,Managing      General Partner |   |    304 |   |    842-3597 |   |   |
|-----------------------------------------------------------------------------------------------------------------------|--------|-----------------------|--------|----------------------------|--------|--------|
| (Name)                                                                                                                |   | (Area      Code)      |   | (Telephone      Number)    |   |   |

| (2)   | Have      all other periodic reports required under Section 13 or 15(d) of the      Securities Exchange Act of 1934 or Section 30 of the Investment      Company Act of 1940 during the preceding 12 months or for such      shorter period that the registrant was required to file such report(s)      been filed ? If answer is no, identify      report(s).          Yes    No      x                                                                                                           |
|-----------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
|            |  Form      10-Q for the quarter ended March 31, 2006Form      10-Q for the quarter ended June 30, 2006Form      10-Q for the quarter ended September 30, 2006Form      10-K for the year ended December 31, 2006Form      10-Q for the quarter ended March 31, 2007Form      10-Q for the quarter ended June 30, 2007Form      10-Q for the quarter ended September 30, 2007Form      10-K for the year ended December 31, 2007Form      10-Q for the quarter ended March 31, 2008Form      10-Q for the quarter ended June 30, 2008Form      10-Q for the quarter ended September 30, 2008 |
|            |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| (3)   | Is      it anticipated that any significant change in results of operations from      the corresponding period for the last fiscal year will be reflected by the      earnings statements to be included in the subject report or portion      thereof?                Yes x      No                                                                                                                                                                                                                                              |

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|     | If      so, attach an explanation of the anticipated change, both narratively and      quantitatively, and, if appropriate, state the reasons why a reasonable      estimate of the results cannot be made. Production      volumes peaked during the quarter ended March 31, 2006, and have decreased      each succeeding quarter.  Average oil and gas prices have      declined steadily each quarter from December 2005 through September 2007      and increased during the fourth quarter of      2007.   Accordingly, we anticipate significant changes in      the results of operations for 2006 and 2007 compared to the results      previously reported for the period from February 9, 2005 (date of      inception) to December 31, 2005.  The following table identifies      significant production information for the Partnership ($ in thousands      except per Mcfe amounts): |
|--------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|

|              |   |   |    |   |               |   |   |       |   |   | Per      Mcfe |   |
|-------------------|--------|--------|---------|--------|--------------------|--------|--------|------------|--------|--------|---------------|--------|
| Year      Ended   |   |   |    |   | Oil      & Gas |   |   | Production |   |   | Average       |   |   | Production |   |
| December      31: |   | Mmcfe  |    |   | Sales              |   |   | Costs      |   |   | Price         |   |   | Costs |   |
| 2007              |   |   | 1,401.4 |   |               | $      | 7,988  |       |   | $      | 2,187         |   |   | $ | 5.70 |   |   | $ | 1.56 |   |
| 2006              |   |   | 2,454.9 |   |               |   | 16,235 |       |   |   | 1,746         |   |   |   | 6.61 |   |   |   | 0.71 |   |
| 2005              |   |   | 1,329.2 |   |               |   | 11,626 |       |   |   | 1,537         |   |   |   | 8.75 |   |   |   | 1.16 |   |

|   |  Note:      2005 amounts taken from the Report on Form 10-K filed September 8,      2006.  2006 and 2007 amounts are based on internal unaudited      information. There      could be other significant changes in the results of operations including      changes resulting from the eventual resolution of the production tax issue      discussed in Part III above.  Such changes, if any, will be      discussed in future filings.  |
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|                                    |   |   |   |                                                                                                                           |
|-----------------------------------------|--------|--------|--------|--------------------------------------------------------------------------------------------------------------------------------|
| Date:  November 14,      2008 |   | By     |   | /s/ Richard W.McCullough                                                                                                       |
|                                    |   |   |   | Richard      W. McCullough,Chairman      and Chief Executive Officer of Petroleum      Development Corporation  |