Eos Energy Enterprises, Inc. filed an 8-K with the U.S. Securities and Exchange Commission on September 14, 2026, disclosing that the Federal Financing Bank funded a third advance of $87,018,601 under its DOE-guaranteed promissory note on September 10, 2026.

Key Highlights

  • Third advance funded: The Federal Financing Bank disbursed $87,018,601 to Eos Energy on September 10, 2026, under the FFB Promissory Note.
  • Advance request timing: The company delivered its third advance request to the DOE and FFB on August 24, 2026.
  • Maximum principal: The FFB Promissory Note provides for a maximum principal amount of up to $277,497,000, plus capitalized interest of up to $25,953,000.
  • Prior advances: The FFB previously funded an initial advance of $68,279,365 on December 19, 2024, and a second advance of $22,665,635 on July 1, 2025.
  • DOE guarantee: The U.S. Department of Energy has provided a guarantee covering the company's repayment obligations on the term loan borrowings from the FFB.
  • Press release issued: On September 14, 2026, the company issued a press release announcing the third loan advance, attached as Exhibit 99.1 to the filing.

Eos Energy's Third FFB Advance Under DOE Loan Guarantee Facility

According to the filing, the loan arrangement traces to November 26, 2024, when Eos Energy Enterprises, Inc. (NASDAQ:EOSE), the U.S. Department of Energy, and the Federal Financing Bank entered into a Note Purchase Agreement. Under that agreement, the DOE provided a guarantee of the company's obligations to repay term loan borrowings from the FFB, evidenced by a future advance promissory note. The FFB Promissory Note allows for a maximum principal of up to $277,497,000 and capitalized interest of up to $25,953,000, the company disclosed.

The filing reports that the FFB funded an initial advance of $68,279,365 on December 19, 2024, followed by a second advance of $22,665,635 on July 1, 2025. On August 24, 2026, the company delivered a third advance request, and on September 10, 2026, the FFB funded $87,018,601 under the promissory note. The three advances together total $177,963,601 against the stated maximum principal of $277,497,000, based on the figures disclosed in the filing.

The filing notes that a press release announcing the third loan advance was issued on September 14, 2026, and is attached as Exhibit 99.1. The company also noted that the filing contains forward-looking statements, which are the company's own and subject to its cautionary language, including risks such as "timing and availability of future funding under the DOE loan facility," potential defaults, and changes in applicable laws or regulations.

What Was Disclosed

Eos Energy Enterprises disclosed in an 8-K filed September 14, 2026, the creation of a direct financial obligation: a third FFB loan advance of $87,018,601 funded on September 10, 2026, under its DOE-guaranteed promissory note.