Sierra Management Group Data Breach Investigation

Shamis & Gentile P.A., one of the nation's premier class action law firms specializing in data breach cases, is investigating the Sierra Management Group data breach.

If you were affected by the data breach, your sensitive personally identifiable information may have been exposed, and you may be eligible for compensation.

About Sierra Management Group

Sierra Management Group Inc. is a medical practice management and consulting company based in Newcastle, California. Established in 2010, the company operates as a management services organization (MSO), providing business infrastructure and support to independent physician practices.

Their services include revenue cycle management, billing and coding, contract management and quality management. The company works closely with Sierra Medical Partnership, a network of independent physician-owned practices in the greater Sacramento area.

What Happened?

Sierra Management Group discovered unauthorized access to its systems that occurred between December 2025 and March 2026.

The company confirmed the breach was contained and launched an investigation with the help of outside professionals.

On June 3, 2026, Sierra Management Group completed a review of the compromised files and determined that some files containing personal information were accessed and possibly copied.

On March 7, 2026, the ransomware group GENESIS claimed responsibility for the attack on the dark web, stating they had obtained 100 GB of data, including personal and sensitive information.

At this time, names are the only information type confirmed to have been exposed, although other personal information types such as contact details, government-issued ID numbers, or financial account information may have been exposed.

You May Be Entitled to Compensation

If you were affected by the Sierra Management Group data breach, you may be eligible for compensation. Lawyers are ready to help individuals whose personal information was compromised. By joining a class action, you may be able to recover damages for the exposure of your sensitive information.

To find out if you qualify, complete the below form to join the lawsuit investigation.

Sources

• California Attorney General
• Dark web