What factors caused health insurance premium increases post-ACA?

1. Why the subsidy cliff looms largest: the enhanced credits that masked higher prices

Policy changes to the premium tax credit are front and center: the American Rescue Plan/Inflation Reduction Act enhancements that reduced enrollees’ monthly bills through 2025 are scheduled to expire, and analyses show that reverting to smaller, original subsidies would sharply raise what consumers pay at the point of sale — KFF calculates an average annual increase of 114% for subsidy recipients if enhancements lapse, and a 26% average premium jump was already visible in raw premiums for 2026 before taking subsidy expiration into account ^{[2] [3] [7]}.

2. Insurer filings point to medical and pharmacy cost trends, notably GLP‑1s

Beyond subsidy mechanics, insurers’ rate filings and trackers show traditional cost pressures: higher utilization, medical inflation and rising pharmacy trend expectations. Several insurers explicitly cite heavy and growing use of GLP‑1 medicines (approved for diabetes and increasingly used for weight loss) as a material driver of pharmacy cost trends — one insurer projected utilization and script‑mix increases of 18% in 2025 and 7% in 2026 ^[5].

3. Risk‑pool and market composition dynamics: healthier enrollees could drop, raising rates

Analyses and insurer commentary warn that if enhanced credits end, many healthier people who only buy coverage because it became affordable could drop coverage, leaving a sicker, costlier pool. That potential change in who remains enrolled is a classic force pushing insurers to seek higher rates to remain solvent — filings in 2026 showed insurers requesting their largest increases in years, with medians in some samples near double‑digit percentages ^{[6] [5]}.

4. Regulatory and administrative changes also affect affordability and calculations

Separately, changes in how tax credits are calculated and marketplace rules have altered the estimated impact of subsidy changes: KFF notes that both higher 2026 premiums and Trump‑era adjustments to tax‑credit calculations raised projected post‑subsidy costs ^[2]. Policy shifts that change eligibility or calculation methods therefore translate into measurable premium‑payment differences even when gross premiums are unchanged ^{[2] [8]}.

5. Political fights and timing amplify consumer shock and market uncertainty

Political disagreement about whether to extend subsidies has become part of the story. Reporting documents that lack of congressional action and partisan battles have increased uncertainty for consumers and insurers; advocates warn that sticker shock during open enrollment may deter sign‑ups and cause enrollment churn that feeds back into higher requested rates ^{[9] [10] [3]}.

6. Consequences beyond premiums: enrollment, uncompensated care, and state responses

Analysts and provider groups forecast knock‑on effects if subsidies lapse: fewer people enrolling, more uncompensated care burden on hospitals and safety‑net providers, and potential state‑level interventions or supplemental subsidies where politically feasible. Policy briefs and health‑system trackers list these as likely outcomes tied to the scale of premium‑payment increases projected if enhancements end ^{[11] [6] [8]}.

7. Competing interpretations and limits of current reporting

Sources broadly agree that subsidy expiration is the single largest immediate driver of higher out‑of‑pocket premium payments, but they differ on the magnitude and on how much underlying premium (not net payment) increases are driven by medical cost trends versus market design changes. KFF and trackers emphasize the subsidy cliff and revised credit calculations ^{[2] [7]}; insurer filings and health‑system trackers emphasize pharmacy and utilization trends including GLP‑1s as important contributors ^{[5] [6]}. Available sources do not mention long‑term actuarial modeling that isolates each factor precisely beyond the cited estimates (not found in current reporting).

Bottom line: the sharp rise consumers are seeing combines a policy shock (expiring enhanced tax credits and related calculation changes) with genuine rising health and drug costs and market composition effects; which of those dominates for any individual depends on income, state, plan choice and local insurer actions ^{[2] [5] [6]}.