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): August 10, 2015

CVR PARTNERS, LP

(Exact name of registrant as specified in its charter)

2277 Plaza Drive, Suite 500

Sugar Land, Texas 77479

(Address of principal executive offices, including zip code)

Registrant’s telephone number, including area code: (281) 207-3200

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:

On August 10, 2015, CVR Partners, LP (“CVR Partners”) posted an investor presentation to its website at www.cvrpartners.com under the tab “Investor Relations” related to its previously announced agreement to acquire Rentech Nitrogen Partners, L.P. (“Rentech Nitrogen”) via merger. The presentation provides information on both CVR Partners and Rentech Nitrogen and an overview of the strategic rationale for the transaction. The presentation is furnished as Exhibit 99.1 to this Current Report on Form 8-K.

In accordance with General Instruction B.2 of Form 8-K, the information in this Current Report on Form 8-K and Exhibit 99.1 attached hereto are being furnished pursuant to Item 7.01 of Form 8-K and will not, except to the extent required by applicable law or regulation, be deemed filed by CVR Partners for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabilities of that Section, nor will any of such information or exhibits be deemed incorporated by reference into any filing under the Securities Act of 1933, as amended, or the Securities Exchange Act of 1934, as amended, except as expressly set forth by specific reference in such filing.

To the extent required, the information set forth in Item 7.01 is incorporated into this Item 8.01 by reference.

Information for Unitholders

In connection with the proposed transaction, CVR Partners intends to file a registration statement on Form S-4 that will include a prospectus of CVR Partners and a proxy statement of Rentech Nitrogen, and CVR Partners and Rentech Nitrogen intend to file other documents, with the Securities and Exchange Commission (the “SEC”). INVESTORS ARE URGED TO READ THE PROXY STATEMENT/PROSPECTUS AND OTHER RELEVANT DOCUMENTS FILED WITH THE SEC IF AND WHEN THEY BECOME AVAILABLE BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION.

A definitive proxy statement / prospectus will be sent to unitholders of Rentech Nitrogen seeking their approval of the transaction. Investors and security holders may obtain a free copy of the definitive proxy statement / prospectus (when available) and other documents filed by CVR Partners and Rentech Nitrogen with the SEC at the SEC’s website, www.sec.gov. The definitive proxy statement / prospectus (when available) and such other documents relating to CVR Partners may also be obtained free of charge by directing a request to CVR Partners LP, Attn: Investor Relations, 2277 Plaza Drive, Suite 500, Sugar Land, TX 77479. The definitive proxy statement / prospectus (when available) and such other documents relating to Rentech Nitrogen may also be obtained free of charge by directing a request to Rentech Nitrogen Partners, L.P., Attn: Investor Relations, Julie Dawoodjee Cafarella, 10877 Wilshire Blvd., 10th Floor, Los Angeles, CA 90024.

Participants in the Solicitation

CVR Partners, Rentech Nitrogen and their respective directors and executive officers may, under the rules of the SEC, be deemed to be “participants” in the solicitation of proxies in connection with the proposed transaction. Information regarding directors and executive officers of CVR Partners’ general partner is contained in CVR Partners’ Form 10-K for the year ended December 31, 2014, which has been filed with the SEC. Information regarding directors and executive officers of Rentech Nitrogen’s general partner is contained in Rentech Nitrogen’s Form 10-K for the year ended December 31, 2014, which has been filed with the SEC. A more complete description will be available in the registration statement and the proxy statement/prospectus.

This document shall not constitute an offer to sell or the solicitation of an offer to buy, nor shall there be any sale of such securities, in any jurisdiction in which such offer, solicitation or sale would be unlawful prior to appropriate registration or qualification under the securities laws of such jurisdiction. No offering of securities shall be made except by means of a prospectus meeting the requirements of Section 10 of the Securities Act of 1933, as amended.

(d) Exhibits

The following exhibit is being “furnished” as part of this Current Report on Form 8-K:

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.

Date: August 10, 2015

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