California-Based Heart Monitor Maker Breached, Affecting 8,179,772 People – Names, Insurance Numbers, Birth Dates and More at Risk

A California-based heart monitor maker is warning more than eight million people that hackers stole their personal and health information.

iRhythm Holdings says unauthorized individuals accessed and downloaded data from certain third-party-hosted business applications between June 3rd and June 8th.

The U.S. Department of Health and Human Services (HHS) breach portal now lists 8,179,772 people as impacted.

The stolen data includes patient names, addresses, email addresses, phone numbers, dates of birth, iRhythm account numbers, device serial numbers, insurance numbers and dates of service.

“On or around June 8, 2026, iRhythm detected unauthorized access in certain third-party-hosted business applications. Upon detecting the unauthorized access, we promptly implemented our incident response plan. As part of our investigation, we have been working very closely with external cybersecurity professionals experienced in handling these types of incidents. After completing our forensic investigation, we learned certain data we store was accessed and downloaded by unauthorized individuals between June 3 and June 8, 2026.”

iRhythm began notifying impacted people on October 2nd.

Says iRhythm,

“iRhythm has no evidence that any personal information has been or will be used to commit identity theft.”

The company is encouraging those affected to place a fraud alert or security freeze on their credit files and get free credit reports.

iRhythm says its medical devices, clinical systems and patient safety were not affected and that it does not store payment card or financial account information.

The Daily Hodl reported earlier this month that state filings showed more than 368,000 people impacted in Texas and South Carolina.

The San Francisco company is best known for its Zio wearable heart monitor.