California Imposes New Notice Rules on Healthcare M&A

California’s Office of Health Care Affordability (OHCA) has issued proposed emergency regulations creating a mandatory 90-day pre-closing notice regime for many healthcare transactions. The rules, which implement Assembly Bill 1415, specifically target deals involving private equity groups, hedge funds, and management service organizations (MSOs).

Sophisticated counsel and clients care because the filing thresholds are low, capturing private equity or hedge fund acquisitions of as little as 10% of a healthcare entity's assets or equity, along with many common MSO platform and add-on deals. The required disclosures are extensive and similar to a federal Hart-Scott-Rodino filing, demanding sensitive data on ownership, governance, valuation, and debt. This imposes significant new administrative burdens and strategic considerations on transactions that may not otherwise require federal antitrust review, and it makes previously private deal information public record, though a confidentiality process exists. Deal timelines must now account for OHCA's review period, which includes a 45- to 60-day window for the agency to decide whether to conduct a more extensive Cost and Market Impact Review. Dealmakers should monitor for the regulations to be finalized, expected in early October 2026, and adjust Q4 2026 and 2027 transaction plans accordingly.