By HFT Staff

Arrowhead Regional Medical Center (ARMC) recently learned of a data breach incident involving Buchalter, LLP (Buchalter), a law firm that provides legal services to ARMC and had access to certain patient information in connection with those services. 

On August 28, 2026, Buchalter learned that a limited amount of Buchalter data was subject to unauthorized acquisition. In response, Buchalter immediately took steps to confirm the security of its systems and commenced an internal investigation with the assistance of third-party computer forensic specialists to evaluate the scope of the incident. Buchalter has determined that this was an isolated incident and there is no evidence that the incident impacted Buchalter’s network or systems. Buchalter engaged data mining experts to perform a comprehensive review of the affected data. 

On September 4, 2026, Buchalter discovered that a limited amount of ARMC information was contained within the impacted data set and notified ARMC that the incident involved information belonging to certain ARMC patients. Buchalter then worked with ARMC to identify contact information for the purpose of effectuating notice. ARMC’s systems and networks were not impacted by this incident. 

There is currently no evidence that the information has been viewed by any third-party or of any misuse of the impacted information as a result of this incident. 

The information involved in this incident may have included patient names, social security numbers, dates of birth, and other information relating to health insurance claims (such as medical record number, patient account number, dates of service, care setting or status (such as inpatient, outpatient, emergency, or observation) and diagnosis-related group (DRG) code number). 

The data involved in the incident does not include full patient medical records, medical imaging, or financial information, such as credit card or bank account information. 

Upon discovering this incident, Buchalter immediately began an investigation with the assistance of third-party experts and took steps to confirm the security of the Buchalter systems. Additionally, Buchalter has taken steps to reduce the likelihood of a similar incident occurring in the future. Buchalter also reported this matter to law enforcement and will cooperate with any efforts to hold the perpetrator(s) accountable. 

Upon learning of the incident, ARMC promptly began working with Buchalter to evaluate the incident and its impact on ARMC patients. ARMC reviewed information regarding Buchalter’s investigation, worked to identify the individuals and information affected, assessed the nature and scope of the incident, and coordinated appropriate notification and mitigation efforts. ARMC also reviewed the steps taken by Buchalter to contain the incident, strengthen its safeguards and reduce the risk of a similar incident occurring in the future.