Item 1.01 Entry into a Material Definitive Agreement.

On June 5, 2025, Plug Power Inc. (the "Company") entered into a Securities Purchase Agreement (the "Purchase Agreement") with Andrew J. Marsh, the Company's Chief Executive Officer (the "Purchaser"), pursuant to which it issued and sold one (1) share of the Company's newly designated Series F Mirroring Preferred Stock, par value $0.01 per share (the "Series F Mirroring Preferred Stock"), to such Purchaser for an aggregate purchase price of $1,000. The share of the Series F Mirroring Preferred Stock was issued for the sole limited purpose of obtaining the requisite vote of stockholders in connection with the proposal to amend the Company's charter to, at the discretion of the Company's Board of Directors (the "Board"), effect a reverse stock split with respect to the Company's common stock (the "Reverse Stock Split") at the next annual meeting of the Company's stockholders to be held on July 3, 2025 (the "2025 Annual Meeting"), as further described in Item 5.03 of this Current Report on Form 8-K.

The Purchase Agreement contains customary representations and warranties and agreements and obligations of the parties.

The foregoing description of the material terms of the Purchase Agreement does not purport to be complete and is qualified in its entirety by reference to the full text of the Purchase Agreement, a copy of which is filed herewith as Exhibit 10.1 and is incorporated herein by reference.

Item 3.02 Unregistered Sales of Equity Securities.

The information set forth in Item 1.01 of this Current Report on Form 8-K is incorporated herein by reference.

The share of Series F Mirroring Preferred Stock has not been registered under the Securities Act of 1933, as amended (the "Securities Act"), or the securities laws of any state, and was offered and sold in reliance on the exemption from registration under the Securities Act afforded by Section 4(a)(2) thereof.

Item 5.03 Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year.

On June 5, 2025, the Company filed a Certificate of Designation of the Series F Mirroring Preferred Stock (the "Certificate of Designation") with the Secretary of State of the State of Delaware to create a new class of Series F Mirroring Preferred Stock. The Certificate of Designation designates one (1) share of authorized preferred stock as Series F Mirroring Preferred Stock.

The Certificate of Designation provides that the share of Series F Mirroring Preferred Stock will have 45,000,000,000 votes and will vote together with the outstanding shares of the Company's common stock as a single class exclusively with respect to the Reverse Stock Split proposal to be presented at the 2025 Annual Meeting.

The share of Series F Mirroring Preferred Stock will be voted, without action by the holder, on the Reverse Stock Split proposal in the same proportion as shares of common stock are voted on such proposal. The Series F Mirroring Preferred Stock will serve to reflect the voting preference of the holders of common stock that vote on the Reverse Stock Split proposal, whether for or against the proposal, and therefore will not override the stated preference of the holders of common stock who vote their shares for or against the proposal. As an example, if the holders of 50.5% of the common stock that vote at the 2025 Annual Meeting are voted for the Reverse Stock Split proposal, then 50.5% of the vote cast by the holder of the Series F Mirroring Preferred Stock shall be cast for the Reverse Stock Split proposal. The Series F Mirroring Preferred Stock otherwise has no other voting rights, including no right to vote in the election of the Company's directors. The Share of Series F Mirroring Preferred Stock is not convertible into, or exchangeable for, shares of any other class or series of stock or other securities of the Company.

The Company will redeem the Series F Mirroring Preferred Stock promptly following the approval or rejection of the Reverse Stock Split proposal by its stockholders. Upon such redemption, the Purchaser will receive consideration of $1,000 in cash.

The foregoing description of the Certificate of Designation does not purport to be complete and is qualified in its entirety by reference to the full text of the Certificate of Designation, a copy of which is filed herewith as Exhibit 3.1 and is incorporated herein by reference.