MACT Health Board Data Breach

On or about November 12, 2025, MACT Health Board (“MACT”) experienced an incident that disrupted the operations of its IT systems. MACT immediately secured its systems, launched an investigation with the assistance of third‑party forensic experts, and notified law enforcement. The investigation confirmed that an unauthorized party accessed certain files on MACT’s systems between November 12, 2025, and November 20, 2025.

Following the discovery, MACT began reviewing the affected files to determine the specific information involved. This review was completed on January 9, 2026, when MACT determined that the compromised files contained personal information belonging to certain individuals. For many affected patients, this included medical information related to their care. In a separate notification, MACT also informed certain employees that their Social Security numbers and driver’s license numbers were impacted.

MACT Health Board implemented additional safeguards and technical security measures to enhance protection and monitoring of its systems following this incident.

To support impacted individuals, MACT is offering a complimentary 12‑month membership to Experian’s IdentityWorks Credit 3B, which includes triple‑bureau credit monitoring, identity theft restoration, and fraud consultation services. Enrollment does not require a credit card and does not affect credit scores.

MACT Health Board is a tribal healthcare organization serving Mariposa, Amador, Alpine, Calaveras, and Tuolumne counties, providing culturally sensitive medical, dental, behavioral health, optometry, and chiropractic services. Its mission is to improve the health of American Indian and Alaska Native communities through comprehensive care rooted in traditional values.

The compromised data relates to individuals whose personal, financial, or medical information was stored within the systems accessed during the breach.

If you received a Data Breach notification letter from MACT Health Board, it confirms that your personal information may have been accessed by an unauthorized third party.

What information is involved in the MACT Health Board Data Breach?

Compromised information may include:

Your Personally Identifiable Information (PII) includes any data that can identify you, such as your name, date of birth, Social Security number, or driver’s license number. When organizations fail to protect this information, individuals are put at significant risk of identity theft and financial fraud.

Because this breach involves medical information for many affected individuals, some of the compromised data also qualifies as Protected Health Information (PHI). PHI is protected under HIPAA and state privacy laws. Exposure of PHI increases the risk of medical identity theft, healthcare fraud, and misuse of sensitive treatment information.

If your information was included in the affected files, one of the most important steps you can take is enrolling in the free Experian IdentityWorks membership provided by MACT. Impacted individuals should also continue monitoring financial and medical accounts for unusual or unauthorized activity.

MACT’s notification provides instructions for placing a fraud alert or security freeze with the three major credit bureaus — Equifax, Experian, and TransUnion. These measures can help prevent criminals from opening new accounts using your identity.

California residents benefit from additional protections under the California Consumer Privacy Act (CCPA), which grants specific rights related to the handling and safeguarding of personal information. They may also have further legal remedies when personal or financial information is compromised.

If you received a NOTICE OF DATA BREACH letter from MACT Health Board, your personal, financial, and medical information may be at heightened risk. Cybercriminals can misuse this type of data to commit identity theft, insurance fraud, medical fraud, and other crimes.

Contact the Data Breach Lawyers at Emery | Reddy, PC for a Free Case Review today.