In this letter to Congressional leaders, directors of 17 state-based marketplaces express support for extending enhancements to health insurance premium tax credits (PTC) currently included in the proposed Build Back Better Act (BBBA). The enhancements, temporarily enacted through 2022, increased affordability for the millions of Americans who access coverage through the health insurance marketplaces and helped drive enrollment of an additional 2.8 million individuals in coverage this year. As currently proposed, the BBBA would extend PTC enhancements through 2025.