SCHEDULE 13D/A 0001578109 XXXXXXXX LIVE 2 Common Stock, $0.01 par value per share 01/09/2026 false 0001922446 G2891G204 Diversified Energy Co

1600 Corporate Drive Birmingham AL 35242

EIG Asset Management, LLC 202-600-3300 Krisy Lee, Chief Compliance Officer 600 New Hampshire Ave NW, Suite 1200 Washington DC 20037 Y EIG Redwood Co-Investment, L.P. OO N DE 327012.00 0.00 327012.00 0.00 327012.00 N 0.41 PN The percent of class is calculated based on 80,620,444 shares of common stock ("Common Stock") outstanding, as reported by the Issuer in its prospectus, filed with the Securities and Exchange Commission (the "SEC") as Exhibit 99.1 to its Form 6-K on November 20, 2025. Y EIG Energy XV Blocker Agent (Redwood), Inc. OO N DE 283715.00 0.00 283715.00 0.00 283715.00 N 0.35 CO The percent of class is calculated based on 80,620,444 shares of Common Stock outstanding, as reported by the Issuer in its prospectus, filed with the SEC as Exhibit 99.1 to its Form 6-K on November 20, 2025. Y EIG Holdings Carry Splitter (Redwood), L.P. OO N DE 1012758.00 0.00 1012758.00 0.00 1012758.00 N 1.26 PN The percent of class is calculated based on 80,620,444 shares of Common Stock outstanding, as reported by the Issuer in its prospectus, filed with the SEC as Exhibit 99.1 to its Form 6-K on November 20, 2025. Y EIG Energy Fund XV, L.P. OO N DE 742468.00 0.00 742468.00 0.00 742468.00 N 0.92 PN The percent of class is calculated based on 80,620,444 shares of Common Stock outstanding, as reported by the Issuer in its prospectus, filed with the SEC as Exhibit 99.1 to its Form 6-K on November 20, 2025. Y EIG Energy Fund XV-A, L.P. OO N DE 506760.00 0.00 506760.00 0.00 506760.00 N 0.63 PN The percent of class is calculated based on 80,620,444 shares of Common Stock outstanding, as reported by the Issuer in its prospectus, filed with the SEC as Exhibit 99.1 to its Form 6-K on November 20, 2025. 0001578109 N EIG Energy Fund XVI, L.P. OO N DE 2732662.00 0.00 2732662.00 0.00 2732662.00 N 3.39 PN The percent of class is calculated based on 80,620,444 shares of Common Stock outstanding, as reported by the Issuer in its prospectus, filed with the SEC as Exhibit 99.1 to its Form 6-K on November 20, 2025. Y EIG Energy Fund XVI-E, L.P. OO N DE 43947.00 0.00 43947.00 0.00 43947.00 N 0.05 PN The percent of class is calculated based on 80,620,444 shares of Common Stock outstanding, as reported by the Issuer in its prospectus, filed with the SEC as Exhibit 99.1 to its Form 6-K on November 20, 2025. Y EIG Energy Fund XVI Holdings Splitter (FourPoint), L.P. OO N DE 1248819.00 0.00 1248819.00 0.00 1248819.00 N 1.55 PN The percent of class is calculated based on 80,620,444 shares of Common Stock outstanding, as reported by the Issuer in its prospectus, filed with the SEC as Exhibit 99.1 to its Form 6-K on November 20, 2025. Y EIG Energy Fund XV Blocker Series C (FourPoint) LLC OO N DE 603444.00 0.00 603444.00 0.00 603444.00 N 0.75 OO The percent of class is calculated based on 80,620,444 shares of Common Stock outstanding, as reported by the Issuer in its prospectus, filed with the SEC as Exhibit 99.1 to its Form 6-K on November 20, 2025. Common Stock, $0.01 par value per share Diversified Energy Co 1600 Corporate Drive Birmingham AL 35242 This Amendment No. 2 (this "Amendment") amends and supplements the statement on Schedule 13D originally filed with the SEC by the Reporting Persons on May 29, 2025 and Amendment No. 1 filed with the SEC on September 22, 2025 (collectively, the "Schedule 13D"). Capitalized terms used but not defined in this Amendment shall have the meanings ascribed to such terms in the Schedule 13D. Except as specifically provided herein, this Amendment does not modify any of the information previously reported in the Schedule 13D. The information set forth in lines 11 and 13 of each of the cover pages hereto is incorporated by reference into this Item 5. The information (i) set forth or incorporated by reference in Item 4 of this Amendment and (ii) set forth on lines 7 through 10 of each of the cover pages hereto is incorporated by reference into this Item 5. On January 9, 2026, the Reporting Persons agreed to sell 2,100,000 shares of Common Stock of the Issuer in an unregistered block trade pursuant to Rule 144 under the Securities Act of 1933, as amended, at a price of $13.28 per share of Common Stock. Item 7 of the Schedule 13D is hereby amended and supplemented by the addition at the end thereof: 10.3 Amended and Restated Relationship Agreement, between Diversified Energy Company, Diversified Energy Company PLC and EIG Management Company, LLC, dated November 13, 2025 which substituted Diversified Energy Company for Diversified Energy Company PLC under that certain Relationship Agreement, dated March 14, 2025. EIG Redwood Co-Investment, L.P. /s/ Kristin Kelly 01/12/2026 /s/ Kamyar Daneshvar 01/12/2026 EIG Energy XV Blocker Agent (Redwood), Inc. /s/ Kristin Kelly 01/12/2026 EIG Holdings Carry Splitter (Redwood), L.P. /s/ Kristin Kelly 01/12/2026 /s/ Kamyar Daneshvar 01/12/2026 EIG Energy Fund XV, L.P. /s/ Kristin Kelly 01/12/2026 /s/ Kamyar Daneshvar 01/12/2026 EIG Energy Fund XV-A, L.P. /s/ Kristin Kelly 01/12/2026 /s/ Kamyar Daneshvar 01/12/2026 EIG Energy Fund XVI, L.P. /s/ Kristin Kelly 01/12/2026 /s/ Kamyar Daneshvar 01/12/2026 EIG Energy Fund XVI-E, L.P. /s/ Kristin Kelly 01/12/2026 /s/ Kamyar Daneshvar 01/12/2026 EIG Energy Fund XVI Holdings Splitter (FourPoint), L.P. /s/ Kristin Kelly 01/12/2026 /s/ Kamyar Daneshvar 01/12/2026 EIG Energy Fund XV Blocker Series C (FourPoint) LLC /s/ Kristin Kelly 01/12/2026 /s/ Kamyar Daneshvar 01/12/2026