How does ACA subsidy reliance vary by state in 2024?

1. High nationwide reliance: subsidies reached the vast majority of enrollees

National reporting finds that an overwhelming share of marketplace enrollees received premium tax credits in 2024 — about 9 in 10 — meaning most consumers’ monthly payments were set by income-based subsidies rather than raw plan prices ^[1]. That national concentration explains why changes to federal policy (like letting IRA enhancements expire) would shift costs for a very large number of people ^[3].

2. Why states differ: Medicaid expansion, enrollment mix, and benchmark prices

State variation stems from three structural factors. First, whether a state expanded Medicaid affects who qualifies for marketplace subsidies — nonexpansion states leave a coverage gap that changes the pool eligible for credits (available sources do not mention each Medicaid expansion state by name but discuss the role of expansion in eligibility, p1_s6). Second, the local mix of enrollees (income distribution, ages) influences average subsidy size; California’s analysis shows many Covered California enrollees are low- or moderate-income and therefore receive large ACA and IRA subsidies on average ^[2]. Third, benchmark plan prices and insurer market dynamics (entries/exits) change subsidy amounts because credits are tied to the second-lowest-cost silver plan in each area ^{[4] [5]}.

3. State-run supplements and targeted programs blunt — but don’t erase — federal dependence

Several states operate their own premium help or programmatic alternatives that alter reliance on federal credits. New Mexico’s expanded cost‑sharing and some Basic Health Programs (BHPs) like Minnesota’s and Oregon’s provide heavily subsidized coverage for lower-income residents, sometimes up to 200–300% of the federal poverty level, shifting enrollment and out-of-pocket burdens locally ^[6]. Colorado and Washington implemented state-funded subsidies (Cascade Care Savings, Health Care Affordability Fund) with income caps and eligibility rules that interacted with federal credits in 2024 — but these programs are often limited in eligibility or funding and therefore do not fully replace federal subsidies ^[7].

4. Who would be hit hardest if federal enhancements lapse — and where

Analysts and interactive tools project outsized premium increases and potential coverage loss if IRA-enhanced credits expire. KFF’s state-by-state modeling and other projections note that every state could see higher uninsured rates, with the largest increases expected in states that had not expanded Medicaid and where marketplace enrollees are especially subsidy-dependent ^{[3] [8]}. The UC Berkeley example for California shows IRA and ACA credits together covered the large majority of premiums for many enrollees — illustrating that states with many subsidized enrollees would face big premium shocks without extensions ^[2].

5. Political and administrative variation complicates the picture

State political choices affect exposure: some governors and legislatures have created state subsidy programs or marketplace designs that reduce out-of-pocket costs for residents, while others have challenged federal rules (for example, litigation around DACA-related enrollment is noted in reporting) and differing marketplace platforms required insurers to file alternative rate scenarios depending on whether federal enhancements continued ^{[9] [10]}. POLITICO reported that exchanges prepared dual rate filings anticipating either continuation or expiration of enhanced subsidies, signaling administrative complexity and state-level contingency planning ^[10].

6. Limitations and gaps in available reporting

Available sources provide strong national and example-based state detail (e.g., California, New Mexico, Colorado), but do not supply a single, complete 50‑state table in this file quantifying subsidy reliance by percentage for each state in 2024. Specific state-level breakdowns (exact share of enrollees receiving subsidies in every state, dollar averages per enrollee by state) are available through KFF and CMS databases referenced by analysts but are not reproduced in the sources provided here (available sources do not mention a full 50-state dataset in these excerpts; see ^[1] and ^[3] for discussed analyses).

Bottom line: In 2024, most marketplace enrollees nationally relied on ACA premium tax credits (about 9 in 10), but state reliance varied meaningfully due to Medicaid expansion status, state-funded subsidy programs, local benchmark premiums, and enrollment mix; those variations determine which states would face the biggest coverage and affordability impacts if federal enhancements were not extended ^{[1] [2] [3]}.