What are the projected costs and coverage impacts of GOP ACA replacement proposals according to CBO or independent analysts?

1. Big-picture CBO cost and coverage estimates: headline numbers

CBO’s scoring found the 2025 reconciliation changes would reduce federal marketplace and Medicaid spending by hundreds of billions over a decade and increase the number of uninsured by about 10 million by 2034 from the law’s Medicaid and Marketplace provisions alone — and that combined with the likely expiration of enhanced premium tax credits could push the uninsured increase above 14 million in 2034 ^[2]. Separately, CBO estimated not extending the ARPA‑era enhanced premium tax credits would cut Marketplace spending by roughly $335 billion and raise the uninsured by about 4.2 million by 2034 in one framing; in other CBO publications the permanent extension of ARPA‑style credits was estimated to increase deficits by roughly $350 billion while adding about 3.8 million insured in 2035 ^{[1] [5] [3]}.

2. How Republican proposals translate to fewer covered people

CBO’s work attributes uninsured growth to three channels in the reconciliation package: Medicaid changes (about 7.5 million more uninsured in 2034), Marketplace changes (about 2.1 million), and other interactions (about 0.4 million), summing to roughly a 10 million net increase by 2034 versus the prior baseline — and that figure rises when ARPA enhancements expire as previously counted in CBO baselines ^[2]. CBO also scored discrete GOP Medicaid proposals (work requirements, tighter eligibility/renewal rules, provider‑tax limits) and found millions of enrollment reductions — for example, certain repeals or regulatory changes would reduce enrollment by millions and generate large federal savings ^{[6] [7]}.

3. Marketplace math: premiums, tax credits and enrollment

CBO’s analysis shows the mechanics: higher premiums and reduced premium tax credit generosity push people off Marketplace plans. If the enhanced credits expire, CBO projects gross benchmark premiums would rise (e.g., 4.3% in 2026 and averaging 7.9% 2026–2034 in one report) and millions would disenroll — CBO’s estimates cited 2.2 million uninsured in 2026 rising to ~3.8 million annually in later years if credits lapse ^{[3] [8]}. Brookings and KFF syntheses emphasize that failing to extend credits or making structural changes to Marketplace rules would allow higher premiums and lower enrollment — Brookings notes a roughly one‑third fall in Marketplace enrollment when the 2025 bill’s choices (including not extending credits) are taken together ^[1].

4. Fiscal tradeoffs emphasized by CBO and allies

CBO and JCT estimates show policy design matters: permanently continuing ARPA‑style credits would raise deficits (CBO/JCT numbers cited by congressional offices: roughly $335–$350 billion over a decade in different publications) while increasing insured counts by several million ^{[5] [1]}. Conversely, policies intended to save federal dollars — cutting provider taxes, tightening Medicaid rules, or not extending credits — produce large federal savings but translate into state budget pressures and coverage losses, per CBO and independent analysts ^{[6] [9]}.

5. Independent analysts’ context and state‑level concerns

KFF, CBPP, and academic analysts translate CBO’s national scores into state and subgroup impacts, showing Medicaid reductions and marketplace changes disproportionately hit expansion states and low‑income people; CBPP and California‑focused analyses warn of shifted costs to states and reduced access to care if provider‑tax changes and work requirements are enacted ^{[10] [4] [9]}. KFF’s state breakdowns allocate CBO’s national coverage losses and find variation across states in projected uninsured increases ^[2].

6. Competing framings and political implications

Republicans frame proposals as reducing federal overreach or reallocating assistance (examples of proposals include swapping credits for HSAs), but CBO’s independent scoring repeatedly shows such alternatives either increase the deficit if credits are extended permanently or reduce federal spending while increasing uninsured if credits lapse or Medicaid rules tighten ^{[11] [5] [3]}. Democratic and advocacy summaries emphasize the human cost — millions losing coverage and premium shocks — while conservative outlets emphasize fiscal restraint and alternatives; both cite CBO numbers but highlight different policy tradeoffs ^{[1] [12]}.

Limitations and caveats: CBO’s estimates depend on baseline assumptions (including whether ARPA enhancements are assumed to expire), the precise policy text, and behavioral responses; independent groups re‑allocate CBO’s national numbers to states with modeling choices that create variation in estimates ^{[2] [5]}. Available sources do not mention every GOP proposal’s final legislative text or post‑enactment administrative choices — real outcomes will hinge on those details (not found in current reporting).