The One Big Beautiful Bill Act (OBBBA) makes significant changes to ACA subsidies, premium tax credits, and related rating and coverage provisions in the individual market. Its subsidy and premium adjustments layer onto existing ACA marketplace dynamics, where enrollment and pricing already respond closely to policy and economic shifts. As OBBBA provisions phase in, federal and state officials are reassessing funding levels, reinsurance, and other stabilization tools with implications for marketplace affordability, plan participation, and consumer coverage through 2026 and beyond.