Horizon Healthcare RCM

Horizon Healthcare RCM notified Vermont AG of a ransomware incident occurring Dec 26-27, 2024. Files were encrypted and copied. Data included names and government IDs. Horizon restored systems, had attacker delete data, and offers Kroll identity monitoring. No specific count disclosed.

Horizon Healthcare RCM, a revenue-cycle management provider, reported a supplemental data breach affecting 11 Maine residents. The incident, occurring Dec 26-27, 2024, involved a computer virus encrypting files and unauthorized copying of patient data (names and government identifiers). Notices were sent Nov 26, 2025, offering 12 months of Kroll identity monitoring.

Horizon Healthcare RCM notified Montana residents of a ransomware incident discovered on December 27, 2024. Attackers encrypted files and exfiltrated data containing names and government IDs between Dec 26-27, 2024. Horizon restored systems, engaged Kroll for identity monitoring, and enhanced security measures.

Horizon Healthcare RCM, a revenue-cycle management provider, issued a supplemental data breach notice to the New Hampshire Attorney General on November 26, 2025. The incident involved a computer virus (ransomware) that encrypted files and resulted in unauthorized copying of patient data between December 26-27, 2024. Approximately 10 New Hampshire residents were affected. The breach involved names and other personal information. Horizon engaged Kroll for identity monitoring and implemented enhanced security measures.

HORIZON HEALTHCARE RCM filed a data-breach notice with the Illinois Attorney General in July 2025 (case 25-07-271). The register records the breach as discovered on December 27, 2024. Personal information types reported: drivers license, financial account number, medical information, ssn. Illinois does not publish the number of people affected — 815 ILCS 530/10 permits the Attorney General to publish only the entity name, the types of personal information and the date range.

Horizon Healthcare RCM reported to HHS on 06/27/2025 a Hacking/IT Incident affecting 210901 individuals. Breached information located on Network Server.

Horizon Healthcare RCM reported a data breach to the Indiana Attorney General. The breach occurred on 2024-12-25 and was reported on 2025-06-27. 47,404 Indiana residents were affected. 77,410 individuals affected in total.

Horizon Healthcare RCM, a former revenue-cycle management company, issued a supplemental notice regarding a December 2024 ransomware incident. A computer virus encrypted files and data was copied between Dec 26-27, 2024. The incident affected patient information (names and other data elements) of individuals who received services from a former Horizon customer. Horizon restored systems, arranged for data deletion by the attacker, and provided complimentary Kroll identity monitoring.

Horizon Healthcare RCM disclosed a December 2024 ransomware incident affecting 11 Nebraska residents. A computer virus encrypted files, and data was copied without permission. Affected data included names and Social Security numbers. Horizon notified federal law enforcement, restored systems, and provided 12 months of credit monitoring via Kroll to affected individuals. Notices were sent starting June 27, 2025.

Horizon Healthcare RCM reported a data breach to the Massachusetts Office of Consumer Affairs and Business Regulation. The breach was reported on 2025-06-27. 62 Massachusetts residents were affected.

Horizon Healthcare RCM notified the NH AG of a ransomware incident on Dec 27, 2024. Attackers encrypted files and copied data containing names and SSNs of ~14 NH residents between Dec 26-27, 2024. Horizon restored systems, engaged law enforcement, and provided 12 months of credit monitoring.

Horizon Healthcare RCM reported a cybersecurity incident to the Maine Attorney General affecting 6 Maine residents. The breach occurred on December 26-27, 2024, when a computer virus locked access to files (ransomware) and files were copied without permission. The breach was discovered on May 20, 2025, after an intensive review. Affected data included names and Social Security numbers. Horizon notified federal law enforcement, implemented additional safeguards, and provided 12 months of credit monitoring through Kroll to affected individuals.