Eos Energy Enterprises, Inc.

Rule 10b5-1 Trading Plans

Our directors and officers (as defined in Section 16 of the Exchange Act (“Section 16”)) may from time to time enter into plans for the purchase or sale of Eos stock that are intended to satisfy the affirmative defense conditions of Rule 10b5-1(c) under the Exchange Act.

On March 14, 2025, the following Section 16 officers adopted a “Rule 10b5-1 trading arrangement” (as defined in Item 408 under Regulation S-K of the Exchange Act):

•Joseph Mastrangelo, Chief Executive Officer and Director

•Nathan Kroeker, Chief Commercial Officer

•Michael Silberman, Chief Legal Officer and Corporate Secretary

•Sumeet Puri, Chief Accounting Officer

The Rule 10b5-1 trading arrangements described above terminate on March 14, 2026 and provide for the sale of a predetermined percentage of each Section 16 officer’s restricted stock unit award vesting, sufficient to cover the tax liability for each such Section 16 officer.

Amendment to Cerberus Credit Agreement

As previously disclosed, on June 21, 2024, the Company entered into a credit and guaranty agreement (the “Credit Agreement”), and was subsequently amended by that certain omnibus amendment entered into on November 26, 2024 (the “Credit Agreement Amendment”), by and among the Company, certain of the Company’s subsidiaries as guarantors party thereto, CCM Denali Debt Holdings, LP, acting through Cerberus Capital Management II, L.P. (“Cerberus”), as administrative agent and collateral agent and the lenders party thereto from time to time (the “Lenders”), pursuant to which the Lenders have provided a $210.5 million secured multi-draw facility (the “Delayed Draw Term Loan”) that was made in four installments and a $105 million revolving credit facility, to be made available at the Lenders’ sole discretion and only if the Delayed Draw Term Loan is fully funded, on terms and subject to conditions set forth in the Credit Agreement.

On April 30, 2025, the Company entered into that certain First Amendment to Credit and Guaranty Agreement, by and among the Company, certain of the Company’s subsidiaries as guarantors thereto and the Lenders, pursuant to which, the measurement period for achieving Sales Milestone 4 (as defined in the Credit Agreement) was extended until July 31, 2025. On April 30, 2025, the Company and Cerberus mutually agreed that the Company achieved three of the four Fourth Milestone Components (as defined in the Credit Agreement) related to the Company’s materials cost, Z3 technology and automated line. No additional Preferred Stock or Warrants will be issued to Cerberus related to the three Fourth Milestone Components achieved by the Company. With this achievement, the Company has achieved, to date, a total of fifteen of the sixteen possible Milestone Components (as defined in the Credit Agreement). If the Company fails to meet Sales Milestone 4 on July 31, 2025, then the Applicable Percentage is subject to up to a final 1% increase, and as a result Cerberus would be entitled to receive Preferred Stock or Warrants aggregating to a maximum aggregate Applicable Percentage of 34% (as compared to the original maximum adjustment for all four Milestones of up to 49%), or assuming the number of the Company’s outstanding shares of common stock on a fully diluted basis does not change after April 30, 2025, Preferred Stock and Warrants with respect to an aggregate of 166,645,514 shares of common stock, including the securities already issued to Cerberus.