Current Report Filing Summary

iRhythm Holdings, Inc. reported a material cybersecurity incident on June 10, 2026. The company identified unauthorized activity on third-party-hosted business applications on June 8, 2026, and subsequently received communications from a threat actor claiming to have exfiltrated sensitive information, including proprietary data, patient protected health information, and other personal information, demanding payment for non-disclosure. The company has confirmed data exfiltration and is investigating the nature and scope of the incident. While the incident did not impact products, patient safety, or operations, and does not involve clinical systems or financial information, the company is assessing the potential impact. Cybersecurity insurance may cover some losses. The company will amend the report as more information becomes available.