Nearly 1 Million Social Security Numbers Exposed in Medicare Data Breach

A data breach at a Medicare contractor may have compromised sensitive information, including Social Security numbers, of nearly 1 million beneficiaries.

A Social Security card sits alongside checks from the U.S. Treasury in Washington on Oct. 14, 2021. Kevin Dietsch/Getty Images

The Social Security numbers of nearly one million Medicare beneficiaries may have been exposed in a data breach linked to a vulnerability in software used by a Medicare contractor in Wisconsin, the federal government has announced.

The Centers for Medicare & Medicaid Services (CMS) said in a Sept. 6 news release that a data breach at Wisconsin Physicians Service Insurance Corp. (WPS), one of its contractors, may have exposed the personal information of 946,801 Medicare beneficiaries. The exposed information includes not only names and Social Security numbers but also taxpayer identification numbers, Medicare Beneficiary Identifiers, dates of birth, addresses, and hospital account numbers.