Recent enhancements to the premium tax credit have led to unprecedented growth in the Affordable Care Act Marketplaces, with enrollment reaching 21.4 million in 2024—nearly double the 2020 total. The enhancements are set to expire after 2025. It has been widely reported that expiration would jeopardize health coverage for millions of Americans. But there has been less discussion of when the enhancements must be extended to avert these losses. 

Observers may believe that extending the enhancements to 2026 and beyond can wait until late 2025 or even 2026, since Congress commonly extends tax rules just before or even after expiration. But Congress’s real deadline to avert 2026 premium increases and coverage losses is in the spring of 2025. That’s because most consumers will make 2026 coverage decisions in the fall of 2025, with their options determined by steps that come months earlier: insurance rate-setting, eligibility system updates, and Marketplace communications with enrollees. Unless Congress acts, higher rates would be locked in summer 2025, and consumers would make enrollment decisions in fall 2025 believing they face higher prices—likely resulting in substantial attrition. These losses would be unlikely to be reversed even if the enhanced PTCs were later restored, given widespread reliance on automatic re-enrollment. As a result, waiting to enact an extension would provide substantially less benefit than the exact same legislation passed earlier.