UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, DC 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): January 8, 2013

AMERICAN REALTY CAPITAL PROPERTIES, INC.

(Exact name of Registrant as specified in its charter)

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:

Item 8.01. Other Events.

On December 14, 2012, American Realty Capital Properties, Inc., a Maryland corporation, which we refer to as “we,” “us” or “our,” entered into an Agreement and Plan of Merger with American Realty Capital Trust, III, Inc., a Maryland corporation, or ARCT III, Tiger Acquisition, LLC, a Delaware limited liability company and one of our wholly owned subsidiaries, or Merger Sub, ARC Properties Operating Partnership, L.P., a Delaware limited partnership, or our Operating Partnership, and American Realty Capital Operating Partnership III, L.P., a Delaware limited partnership and the operating partnership of ARCT III, or the ARCT III Operating Partnership. The merger agreement provides for the merger of ARCT III with and into Merger Sub, with Merger Sub surviving as one of our wholly owned subsidiaries. In addition, the merger agreement provides for the merger of ARCT III Operating Partnership with and into our Operating Partnership, with our Operating Partnership being the surviving entity.

We have filed a post-effective amendment to our Registration Statement on Form S-3 (Registration No. 333-182971), or the Post-Effective Amendment, in order to provide investors with certain information relating to the merger and other matters. The purpose of this Current Report on Form 8-K is to file under the Securities Exchange Act of 1934, as amended, and allow for incorporation by reference, as applicable, certain material information relating to the merger in order that such information may be incorporated by reference into the Post-Effective Amendment.

Such information is provided below and in Exhibits 99.1 – 99.5 attached hereto (which are incorporated by reference herein), and consists of (i) certain financial statements of ARCT III, the entity with which we intend to merge, (ii) certain risk factors relating to the proposed merger, (iii) our unaudited pro forma financial statements assuming we merged with ARCT III as of September 30, 2012, (iv) summary financial statements of FedEx Corporation, which is the parent of the lessee under leases producing, on a pro forma basis assuming our merger with ARCT III, 10.1% of our annualized rental income on a straight-line basis as of September 30, 2012, (v) summary financial statements of Dollar General Corporation, which is the parent guarantor of leases producing, on a pro forma basis assuming our merger with ARCT III, 12.3% of our annualized rental income on a straight-line basis as of September 30, 2012, and (vi) summary financial statements of RBS Citizens, N.A., which is the parent of the lessee under leases producing, on a pro forma basis assuming our merger with ARCT III, 11.9% of our annualized rental income on a straight-line basis as of September 30, 2012.

The following financial statements of ARCT III are incorporated herein by reference:

Item 9.01. Financial Statements and Exhibits.

(d) Exhibits.

SIGNATURES

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