HHS appeals court vacatur of 2025 ACA market stabilization rule

The Department of Health and Human Services is appealing a federal court decision that vacated the 2025 Notice of Benefit and Payment Parameters final rule. The rule contained key program integrity provisions for the ACA marketplaces, including measures aimed at stabilizing risk pools and curbing adverse selection. CMS issued implementation guidance earlier this week, indicating ongoing uncertainty for insurers preparing for the 2027 plan year. The appeal sets up a potential Supreme Court review of HHS's regulatory authority over ACA market stabilization. Monitor the Second Circuit docket for the government's brief, expected in late 2026.