UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

PURSUANT TO SECTION 13 OR 15(d) OF THE

SECURITIES EXCHANGE ACT OF 1934

Date of Report (Date of earliest event reported): November 15, 2011

ANGELES PARTNERS XII, LP

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code (864) 239-1000

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below):

ITEM 1.01. Entry into a Material Definitive Agreement.

As previously disclosed, Angeles Partners XII, LP, a Delaware limited partnership (“AP XII”), AIMCO Properties, L.P., a Delaware limited partnership (“AIMCO OP”), and AIMCO AP XII Merger Sub LLC, a Delaware limited liability company of which AIMCO OP is the sole member (the “Merger Subsidiary”), entered into an Agreement and Plan of Merger, dated as of July 28, 2011 (the “Merger Agreement”), pursuant to which the Merger Subsidiary would be merged with and into AP XII, with AP XII as the surviving entity. On November 15, 2011, AP XII, AIMCO OP and the Merger Subsidiary entered into an Amended and Restated Agreement and Plan of Merger, dated as of November 15, 2011 (the “Amended and Restated Merger Agreement”). Pursuant to the terms of the Amended and Restated Merger Agreement, the cash consideration that holders of units of limited partnership interest (each, a “Unit”) of AP XII may elect to receive upon consummation of the merger decreased from $526.71 to $483.14, and the number of partnership common units of AIMCO OP that holders of Units may elect to receive upon consummation of the merger will be calculated by dividing $483.14 by the average closing price of Apartment Investment and Management Company common stock, as reported on the New York Stock Exchange, over the ten consecutive trading days ending on the second trading day immediately prior to the effective time of the merger. This decrease in consideration is due to changes in the estimated market values of AP XII’s properties, changes in AP XII’s financial position and changes in the market value of its indebtedness.

The foregoing summary of the Amended and Restated Merger Agreement is qualified in its entirety by reference to the Amended and Restated Merger Agreement, which is attached hereto as Exhibit 10.1 and incorporated herein by reference.

Additional Information for Investors:

This communication does not constitute an offer to sell or the solicitation of an offer to buy any securities. AIMCO OP and Apartment Investment and Management Company have filed with the Securities and Exchange Commission a registration statement on Form S-4 that includes an information statement of AP XII relating to the transaction, which also constitutes a prospectus of AIMCO OP and Apartment Investment and Management Company. INVESTORS ARE URGED TO READ THE INFORMATION STATEMENT/PROSPECTUS BECAUSE IT CONTAINS IMPORTANT INFORMATION REGARDING THE TRANSACTION.

The information statement/prospectus and other documents which have been and will be filed with the Securities and Exchange Commission are available free of charge at the SEC’s website, www.sec.gov. You may request a copy of these filings, at no cost, by writing or calling Apartment Investment and Management Company at the following address and telephone number: ISTC Corporation, P.O. Box 2347, Greenville, South Carolina 29602; telephone number (864) 239-1029.

ITEM 9.01. Financial Statements and Exhibits.

(d) The following exhibits are filed with this report:

SIGNATURE

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