UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

PURSUANT TO SECTION 13 OR 15(d) OF THE

SECURITIES EXCHANGE ACT OF 1934

Date of Report (Date of earliest event reported): October 16, 2025

Registrant's telephone number, including area code: (301) 515-7260

Not Applicable

Former name or former address, if changed since last report

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 (see General Instruction A.2 below):

Securities registered pursuant to Section 12(b) of the Act:

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ¨

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ¨

Item 3.03 Material Modification to Rights of Security Holders.

To the extent required by Item 3.03 of Form 8-K, the information contained in Item 5.03 of this Current Report on Form 8-K is incorporated herein by reference.

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

On October 16, 2025, Senseonics Holdings, Inc. (the “Company”) filed a Certificate of Amendment to its Amended and Restated Certificate of Incorporation (the “Amendment”) with the Secretary of State of the State of Delaware to effect the previously disclosed one-for-twenty (1-for-20) reverse stock split (the “Reverse Stock Split”) of its outstanding common stock and a proportional decrease in the total number of authorized shares of its common stock from 1,400,000,000 to 70,000,000 (the “Shares Reduction”). The Amendment will be effective at 4:05 p.m. Eastern Time on October 17, 2025 (the “Effective Time”).

The Amendment provides that, at the Effective Time, every twenty (20) shares of the Company’s issued and outstanding common stock will automatically be combined into one (1) issued and outstanding share of common stock and the authorized shares of the Company’s common stock will be reduced from 1,400,000,000 to 70,000,000, without any change in par value per share. The Reverse Stock Split will affect all shares of the Company’s common stock outstanding immediately prior to the effective time of the Amendment. As a result of the Reverse Stock Split, proportionate adjustments will be made to the per share exercise price and/or the number of shares issuable upon the exercise or vesting of all stock options issued by the Company and outstanding immediately prior to the effective time of the Amendment, which will result in a proportionate decrease in the number of shares of the Company’s common stock reserved for issuance upon exercise or vesting of such stock options and a proportionate increase in the exercise price of all such stock options. In addition, all outstanding restricted stock unit awards and warrants will be proportionately adjusted, and the number of shares reserved for issuance under the Company’s equity compensation plans immediately prior to the effective time of the Amendment will be reduced proportionately.

No fractional shares of the Company’s common stock will be issued as a result of the Reverse Stock Split. Stockholders of record who would otherwise be entitled to receive a fractional share of common stock will receive a cash payment in lieu thereof. The Reverse Stock Split will affect all stockholders proportionately and will not affect any stockholder’s percentage ownership of the Company’s common stock (except to the extent that the Reverse Stock Split results in any stockholder owning only a fractional share).

The Company’s common stock is expected to begin trading on the NYSE American on a Reverse Stock Split-adjusted basis as of the open of trading on October 20, 2025 under the existing ticker symbol “SENS.” The new CUSIP number for the Company’s common stock following the Reverse Stock Split is 81727U303.

The foregoing description is qualified in its entirety by the full text of the Amendment, which is filed as Exhibit 3.1 to this Current Report on Form 8-K and is incorporated herein by reference.

Item 9.01 Financial Statements and Exhibits.

(d) 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.