FORTY-SIXTH AMENDMENT TO THE THIRD AMENDED AND RESTATED AGREEMENT OF LIMITED PARTNERSHIP OF AIMCO PROPERTIES, L.P.

EXHIBIT 4.1

FORTY-SIXTH AMENDMENT TO THE
THIRD AMENDED AND RESTATED AGREEMENT OF
LIMITED PARTNERSHIP OF AIMCO PROPERTIES, L.P.

     This FORTY-SIXTH AMENDMENT TO THE THIRD AMENDED AND RESTATED AGREEMENT OF LIMITED PARTNERSHIP OF AIMCO PROPERTIES, L.P., dated as of February 28, 2005 (this “Amendment”), is being executed by AIMCO-GP, Inc., a Delaware corporation (the “General Partner”), as the general partner of AIMCO Properties, L.P., a Delaware limited partnership (the “Partnership”), pursuant to the authority conferred on the General Partner by Section 7.3.C(7) of the Third Amended and Restated Agreement of Limited Partnership of AIMCO Properties, L.P., dated as of July 29, 1994, as amended and/or supplemented from time to time (the “Agreement”). Capitalized terms used, but not otherwise defined herein, shall have the respective meanings ascribed thereto in the Agreement.

     WHEREAS, on March 11, 2002, Casden Properties, Inc. merged with and into the Previous General Partner (the “Casden Merger”);

     WHEREAS, pursuant to the Casden Merger agreement and related documents, upon completion of each of certain properties and the satisfaction of other conditions, the Previous General Partner has agreed to pay additional, deferred consideration in respect of the Casden Merger, and to purchase the general partner interest in the entities that own each such property;

     WHEREAS, in order to fund such payments with respect to the particular property commonly known as Park La Brea B (a.k.a. The Palazzo East at Park La Brea), the Partnership has loaned $85,411,947.12 to the Previous General Partner, which loan is evidenced by a promissory note, dated February 28, 2005, in the original principal amount of $85,411,947.12;

     WHEREAS, the Previous General Partner has contributed to the Partnership the assets acquired in connection with the Casden Merger, including the general partner interest described above and, in connection with such contribution, the Partnership proposes to issue to the Special Limited Partner 3,416,478 Class Thirteen Partnership Preferred Units; and

     WHEREAS, pursuant to Section 4.2.A of the Agreement, the General Partner is authorized to determine the designations, preferences and relative, participating, optional or other special rights, powers and duties of Partnership Preferred Units.

     NOW, THEREFORE, in consideration of the foregoing, and other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the parties hereto agree as follows:

     IN WITNESS WHEREOF, this Amendment has been executed as of the date first written above.

EXHIBIT XX

PARTNERSHIP UNIT DESIGNATION OF THE
CLASS THIRTEEN PARTNERSHIP PREFERRED UNITS
OF AIMCO PROPERTIES, L.P.

      1.  Number of Units and Designation.

     A class of Partnership Preferred Units is hereby designated as “Class Thirteen Partnership Preferred Units,” and the number of Partnership Preferred Units constituting such class shall be 3,416,478.

      2.  Definitions.

     For purposes of the Class Thirteen Partnership Preferred Units, the following terms shall have the meanings indicated in this Section 2, and capitalized terms used and not otherwise defined herein shall have the meanings assigned thereto in the Agreement:

" Agreement ” shall mean the Third Amended and Restated Agreement of Limited Partnership of the Partnership, dated as of July 29, 1994, as amended.

“AIMCO” shall mean Apartment Investment and Management Company, a Maryland corporation.

" Class Thirteen Partnership Preferred Unit ” means a Partnership Preferred Unit with the designations, preferences and relative, participating, optional or other special rights, powers and duties as are set forth in this Exhibit XX .

“Code” shall mean the Internal Revenue Code of 1986, as amended from time to time, or any successor statute thereto. Reference to any provision of the Code shall mean such provision as in effect from time to time, as the same may be amended, and any successor thereto, as interpreted by any applicable regulations or other administrative pronouncements as in effect from time to time.

" Distribution Payment Date ” shall mean December 31 of any year beginning with December 31, 2005, and continuing until no Class Thirteen Partnership Preferred Units remain outstanding.

" Junior Partnership Units ” shall have the meaning set forth in paragraph (c) of Section 7 of this Exhibit XX.

XX-1

" Liquidation Preference ” shall mean, with respect to each Class Thirteen Partnership Preferred Unit, as of any date, Twenty-Five Dollars ($25.00), plus an amount equal to all distributions (whether or not declared or earned) accumulated, accrued and unpaid on such Class Thirteen Partnership Preferred Unit as of such date.

" Parity Partnership Units ” shall have the meaning set forth in paragraph (b) of Section 7 of this Exhibit XX .

" Partnership ” shall mean AIMCO Properties, L.P., a Delaware limited partnership.

" Promissory Note ” shall mean the Promissory Note, dated February 28, 2005, in the original principal amount of $85,411,947.12, made by AIMCO in favor of the Partnership (bearing simple interest at 5.25%, payable on December 31 of each year).

" Senior Partnership Units ” shall have the meaning set forth in paragraph (a) of Section 7 of this Exhibit XX .

      3.  Distributions.

     On every Distribution Payment Date, the holders of Class Thirteen Partnership Preferred Units shall be entitled to receive distributions payable in cash in an amount equal to $1.3125 per Class Thirteen Partnership Preferred Unit. Each such distribution shall be payable to the holders of record of the Class Thirteen Partnership Preferred Units, as they appear on the records of the Partnership at the close of business on the Distribution Payment Date. Distributions shall accumulate from the date of original issuance of the Class Thirteen Partnership Preferred Units.

      4.  Liquidation Preference.

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