UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K/A

(Amendment No. 1)

CURRENT REPORT

PURSUANT TO SECTION 13 OR 15(d)

OF THE SECURITIES EXCHANGE ACT OF 1934

Date of Report (Date of earliest event reported): July 16, 2015 (July 16, 2015)

GENESIS ENERGY, L.P.

(Exact name of registrant as specified in its charter)

(713) 860-2500

(Registrant’s telephone number, including area code)

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:

EXPLANATORY NOTE

On July 16, 2015, Genesis Energy, L.P. (“Genesis”) filed a Current Report on Form 8-K (the “Initial Report”) to report that Genesis entered into a purchase and sale agreement (the “Purchase Agreement”) with Enterprise Products Operating LLC (“EPO”) on July 16, 2015. This Amendment No. 1 to Current Report on Form 8-K/A (the “Amended Report”), which amends the Initial Report, is being filed to include the Purchase Agreement as Exhibit 2.1 to the Initial Report. Except for and as described in this Explanatory Note, no other changes have been made to the Initial Report, and this Amended Report does not amend or update any other information set forth in the Initial Report.

The summary of the Purchase Agreement in the Initial Report is qualified in its entirety by reference to the full text of the Purchase Agreement, a copy of which is attached as Exhibit 2.1 to this Amended Report and incorporated into Item 1.01 of the Initial Report by reference.

The Purchase Agreement contains representations, warranties and other provisions that were made only for purposes of the Purchase Agreement and as of specific dates and were solely for the benefit of the other party thereto. The Purchase Agreement is a contractual document that establishes and governs the legal relations among the parties thereto and is not intended to be a source of factual, business or operational information about Genesis or EPO and their respective subsidiaries or the assets to be acquired from EPO and its affiliates. The representations and warranties made by Genesis and EPO in the Purchase Agreement may be (i) qualified by disclosure schedules containing information that modifies, qualifies or creates exceptions to such representations and warranties and (ii) subject to standards of materiality applicable to the contracting parties that differ from those applicable to investors. Accordingly, investors and security holders should not rely on such representations and warranties as characterizations of the actual state of facts or circumstances.

The following materials are filed as 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.

EXHIBIT INDEX