| OMB APPROVAL                                                                                                                   |
|--------------------------------------------------------------------------------------------------------------------------------|
| OMB Number:  3235-0058Expires:   August 31, 2015Estimated average burdenhours per response  2.50 |
| SEC FILE NUMBER333-41977-08                                                                                                    |
| CUSIP NUMBER                                                                                                              |

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

|   |   | For Period Ended December 31, 2013                                                                                   |
|--------|--------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
|   |   |                                                                                                                                                                                                                                                                    |   | 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. |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|

|                                                      |
|-----------------------------------------------------------|
| PART I — REGISTRANT INFORMATION                     |
|  CO and PA 1999D Limited Partnership                 |
| Full Name of Registrant                                   |
|                                                      |
| Former Name if Applicable                                 |
|                                                      |
| 1775 Sherman Street, Suite 3000                           |
| Address of Principal Executive Office (Street and Number) |
|                                                      |
| Denver, CO  80203                               |
| 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                                                                                                                                                                                                                                                                                                                                                                            |   |  x |
| (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.                                                                                                                                                                                                                                                                                                                                                                                           |   |    |

----

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

| R. Scott Meyers          |        |               |
|--------------------------|-------------|--------------------|
| Chief Accounting Officer |        |               |
| PDC Energy, Inc.,        |        |               |
| 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-K for the period from December 31, 1999 (date of inception) to December 31, 1999 (filing subsequently withdrawn)Form 10-Q for the quarter ended March 31, 2000 (filing subsequently withdrawn)Form 10-Q for the quarter ended June 30, 2000 (filing subsequently withdrawn)                                                                                                                                                                |

----

|   | Form 10-Q for the quarter ended September 30, 2000 (filing subsequently withdrawn)Form 10-K for the year ended December 31, 2000 (filing subsequently withdrawn)Form 10-Q for the quarter ended March 31, 2001 (filing subsequently withdrawn)Form 10-Q for the quarter ended June 30, 2001 (filing subsequently withdrawn)Form 10-Q for the quarter ended September 30, 2001 (filing subsequently withdrawn)Form 10-K for the year ended December 31, 2001 (filing subsequently withdrawn)Form 10-Q for the quarter ended March 31, 2002 (filing subsequently withdrawn)Form 10-Q for the quarter ended June 30, 2002 (filing subsequently withdrawn) Form 10-Q for the quarter ended September 30, 2002 (filing subsequently withdrawn)Form 10-K for the year ended December 31, 2002 (filing subsequently withdrawn)  Form 10-Q for the quarter ended March 31, 2003 (filing subsequently withdrawn)Form 10-Q for the quarter ended June 30, 2003 (filing subsequently withdrawn)Form 10-Q for the quarter ended September 30, 2003 (filing subsequently withdrawn)Form 10-K for the year ended December 31, 2003 (filing subsequently withdrawn)Form 10-Q for the quarter ended March 31, 2004 (filing subsequently withdrawn)Form 10-Q for the quarter ended June 30, 2004 (filing subsequently withdrawn)Form 10-Q for the quarter ended September 30, 2004 (filing subsequently withdrawn)Form 10-K for the year ended December 31, 2004 (filing subsequently withdrawn)Form 10-Q for the quarter ended March 31, 2005 (filing subsequently withdrawn)Form 10-Q for the quarter ended June 30, 2005Form 10-Q for the quarter ended September 30, 2005Form 10-K for the year ended December 31, 2005Form 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, 2008Form 10-K for the year ended December 31, 2008Form 10-Q for the quarter ended March 31, 2009Form 10-Q for the quarter ended June 30, 2009Form 10-Q for the quarter ended September 30, 2009Form 10-K for the year ended December 31, 2009Form 10-Q for the quarter ended March 31, 2010Form 10-Q for the quarter ended June 30, 2010Form 10-Q for the quarter ended September 30, 2010Form 10-K for the year ended December 31, 2010Form 10-Q for the quarter ended March 31, 2011Form 10-Q for the quarter ended June 30, 2011Form 10-Q for the quarter ended September 30, 2011Form 10-K for the year ended December 31, 2011Form 10-Q for the quarter ended March 31, 2012Form 10-Q for the quarter ended June 30, 2012Form 10-Q for the quarter ended September 30, 2012Form 10-K for the year ended December 31, 2012Form 10-Q for the quarter ended March 31, 2013Form 10-Q for the quarter ended June 30, 2013Form 10-Q for the quarter ended September 30, 2013 |
|--------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|

----

| (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  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. In June 2013, the Partnership completed the divestiture of all of its Piceance Basin assets for cash consideration of approximately $489,600.  The net proceeds from the assets divestiture were distributed pro rata to the Partnership’s partners in July 2013.In December 2013, the Partnership completed the divestiture of all of its remaining Colorado oil and gas properties for cash consideration of $2,764,000.  The net proceeds from the assets divestiture were retained by the Partnership for payment of Bankruptcy costs or future distribution upon approval of Bankruptcy Court.Recent DevelopmentsAs discussed above, on February 27, 2014, Schneider Downs resigned as the Partnership’s independent public accounting firm. Given the pending Chapter 11 Proceeding, the Partnership does not intend to appoint a new independent registered public accounting firm at this time.In March 2014, the Partnership completed the divestiture of all its remaining oil and gas properties for cash consideration of approximately $113,000.  The net proceeds from this divestiture were retained by the Partnership for payment of Bankruptcy costs or future distribution upon approval by the Bankruptcy Court. We cannot comment on the results of our operations for the years ended December 31, 2013 and 2012 until the ultimate resolution of the matters discussed above.  |
|-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|

|  CO and PA 1999D Limited Partnership    |
|----------------------------------------------|
| __________________________________           |
| (Name of Registrant as specified in charter) |
|                                         |

|                           |   |   |   |                             |
|--------------------------------|--------|--------|--------|----------------------------------|
| Date:  April 1, 2014 |   | By     |   | /s/ Karen Nicolaou               |
|                           |   |   |   | Karen Nicolaou,Responsible Party |