On February 9, 2026, the Centers for Medicare & Medicaid Services released its annual proposed rule governing the Affordable Care Act Marketplaces and insurance reforms. The proposed “Notice of Benefit & Payment Parameters,” includes a broad set of policy and operational changes for 2027 that implement elements of H.R.1, roll back several Biden-era policies, revisit provisions of the Marketplace Integrity final rule, and introduce several new policies. This issue brief reviews provisions of the proposed rule with particular import for State-Based Marketplaces and state insurance departments. Comments on the proposed rule are due by March 13, 2026.