CERTIFICATE OF AMENDMENT OF AMENDED AND RESTATED CERTIFICATE OF INCORPORATION OF IRHYTHM TECHNOLOGIES, INC. iRhythm Technologies, Inc. (hereinafter called the “Corporation”), a corporation organized and existing under and by virtue of the General Corporation Law of the State of Delaware (the “DGCL”), does hereby certify as follows: 1. That the name of this Corporation is iRhythm Technologies, Inc., and that this Corporation was originally incorporated pursuant to the DGCL on September 14, 2006 under the name iRhythm Technologies, Inc. The Amended and Restated Certificate of Incorporation of the Corporation was filed with the Secretary of State of the State of Delaware on October 25, 2016 (the “Amended and Restated Charter”). 2. Amendment to Article VIII. (a) Article VIII of the Amended and Restated Charter is hereby amended and restated in its entirety as follows: “ARTICLE VIII 8.1. Limitation of Liability. To the fullest extent permitted by law, neither a director of the Corporation nor an officer of the Corporation shall be personally liable to the Corporation or its stockholders for monetary damages for breach of fiduciary duty as a director or officer, as applicable. Without limiting the effect of the preceding sentence, if the DGCL is hereafter amended to authorize the further elimination or limitation of the liability of a director or officer, then the liability of a director or officer of the Corporation shall be eliminated or limited to the fullest extent permitted by the DGCL, as so amended. 8.2. Indemnification. The Corporation shall indemnify, to the fullest extent permitted by applicable law, any director or officer of the Corporation who was or is a party or is threatened to be made a party to any threatened, pending or completed action, suit or proceeding, whether civil, criminal, administrative or investigative (a “Proceeding”) by reason of the fact that he or she is or was a director, officer, employee or agent of the Corporation or is or was serving at the request of the Corporation as a director, officer, employee or agent of another Corporation, partnership, joint venture, trust or other enterprise, including service with respect to employee benefit plans, against expenses (including attorneys’ fees), judgments, fines and amounts paid in settlement actually and reasonably incurred by such person in connection with any such Proceeding. The Corporation shall be required to indemnify a person in connection with a Proceeding initiated by such person only if the Proceeding was authorized by the Board of Directors. The Corporation shall have the power to indemnify, to the extent permitted by the DGCL, as it presently exists or may hereafter be amended from time to time, any employee or agent of the Corporation who was or is a party or is threatened to

be made a party to any Proceeding by reason of the fact that he or she is or was a director, officer, employee or agent of the Corporation or is or was serving at the request of the Corporation as a director, officer, employee or agent of another corporation, partnership, joint venture, trust or other enterprise, including service with respect to employee benefit plans, against expenses (including attorneys’ fees), judgments, fines and amounts paid in settlement actually and reasonably incurred by such person in connection with any such Proceeding. 8.3. Change in Rights. Neither any amendment nor repeal of this Article VIII, nor the adoption of any provision of this Certificate of Incorporation inconsistent with this Article VIII, shall eliminate, reduce or otherwise adversely affect any limitation on the personal liability of a director or officer of the Corporation existing at the time of such amendment, repeal or adoption of such an inconsistent provision.” 3. That the foregoing amendment was duly adopted by the Board of Directors of the Corporation in accordance with Sections 141 and 242 of the DGCL and was approved by the holders of the requisite number of shares of capital stock of the Corporation. IN WITNESS WHEREOF, the undersigned has executed this Certificate of Amendment on this 30th day of May, 2024. By: /s/ Quentin Blackford Quentin S. Blackford President and Chief Executive Officer