How Much Did Obamacare Cost the Federal Government?

The Affordable Care Act cost the federal government roughly $140 billion in premium tax credits alone in fiscal year 2025, with federal Medicaid expansion payments adding tens of billions more on top. That gross spending is partially offset by ACA taxes still on the books and by Medicare payment reductions the law built in, but the net cost has drifted well away from what Congress was told to expect. When the law passed in 2010, the Congressional Budget Office and the Joint Committee on Taxation projected it would reduce the federal deficit by about $143 billion over its first decade. Repeals, court rulings, and temporary subsidy expansions have all moved the numbers since.¹

Premium Tax Credits Are the Biggest Line Item

The single largest ACA expenditure is the premium tax credit under 26 U.S.C. § 36B. The credit is paid directly to insurers on behalf of marketplace enrollees, reducing what those individuals owe each month. Under the statute’s permanent structure, households between roughly 100% and 400% of the federal poverty level qualify, with the subsidy shrinking as income rises.²

Two later laws pushed subsidy spending well beyond the ACA’s original design. The American Rescue Plan Act of 2021 temporarily extended eligibility above 400% of poverty and increased subsidy amounts across the board. The Inflation Reduction Act of 2022 kept those enhancements running through 2025. Under that expanded formula, marketplace subsidy spending reached about $140 billion in a single fiscal year. Projected fiscal year 2026 spending falls to around $112 billion once the enhancements expire and the original subsidy structure returns.

Federal Medicaid Expansion Spending

The second-largest commitment is federal money flowing to states that expanded Medicaid to adults earning up to 138% of the federal poverty level. Washington covered 100% of the cost for newly eligible enrollees from 2014 through 2016, then stepped down to a permanent 90% federal share starting in 2020. Participating states cover the remaining 10%.³

Federal expansion spending grew rapidly as enrollment surged past early estimates and more states opted in over time. The pandemic pushed the number higher: enrollment spiked, and a continuous enrollment requirement temporarily kept states from removing people from the rolls. Isolating a single dollar figure is harder here than with marketplace subsidies because expansion money moves through the broader Medicaid program rather than a dedicated budget line. It consistently ranks as the ACA’s second-largest ongoing expense.

Taxes and Medicare Savings That Offset the Spending

The ACA was written to pay for itself. Two surtaxes on high earners survived every round of subsequent legislation and continue producing revenue today.

The Net Investment Income Tax, added under 26 U.S.C. § 1411, imposes a 3.8% surtax on investment income (dividends, capital gains, rental income, and similar earnings) for individuals, estates, and trusts above set income thresholds.⁴ The Additional Medicare Tax adds 0.9% on wages and self-employment income above $200,000 for single filers or $250,000 for joint filers.⁵ Together the two surtaxes generate tens of billions of dollars per year.

On the spending side, the law cut Medicare Advantage payment rates, which had been running well above the cost of covering comparable beneficiaries in traditional Medicare, and slowed the growth of Medicare reimbursement rates for hospitals and other providers. Those adjustments produced long-term Medicare savings that were counted as offsets to ACA coverage costs. Critics called this using Medicare dollars to fund a different program; on paper, the savings scored as real.

The employer shared responsibility provision under 26 U.S.C. § 4980H also generates revenue by penalizing large employers (those with 50 or more full-time workers) that fail to offer affordable coverage when at least one worker receives a marketplace subsidy.⁶

Revenue Provisions Congress Later Repealed

The 2010 fiscal balance assumed every ACA tax stayed in place. Several did not.

The individual mandate penalty was reduced to zero dollars by the Tax Cuts and Jobs Act of 2017, effective in 2019. Beyond the direct revenue loss, zeroing out the penalty pulled healthier people out of the marketplace, which raised premiums and enlarged per-person subsidy costs.
The medical device excise tax, originally 2.3% on the sale price of certain devices, went on moratorium in 2016 and was formally repealed in December 2019.⁷
The health insurer fee under ACA Section 9010, an annual fee on health insurance providers based on market share, generated roughly $20 billion per year. Congress suspended it multiple times before repealing it permanently in December 2019.
The Cadillac tax, a 40% excise tax on employer-sponsored plans with premiums above a set threshold, was projected by CBO to raise roughly $193 billion over 2022 through 2029. Congress delayed it repeatedly and repealed it in 2019 before it ever took effect.

The cumulative hit is large. The health insurer fee alone was worth about $20 billion a year, the Cadillac tax would have raised more over time, and the mandate penalty did double duty by generating revenue and keeping healthier people in the risk pool. None of these have been replaced.

Silver Loading Quietly Raised the Bill

In 2017 the federal government stopped making direct payments to insurers for cost-sharing reductions, the discounts that lower deductibles and copays for marketplace enrollees below 250% of the federal poverty level. Insurers are still legally required to provide those discounts, so they built the unreimbursed cost into silver-tier plan premiums, a workaround known as silver loading.

Marketplace subsidies are calculated off the price of silver plans. When silver premiums rise artificially, the benchmark for subsidy calculations rises with them, and the federal government pays larger premium tax credits across the board. Estimates suggest that directly funding cost-sharing reductions would lower gross silver premiums by 10% to 20% and reduce federal deficits by roughly $50 billion over a decade. The government now spends more on subsidies than it would if it simply paid the cost-sharing reductions directly, and Congress has not restored those payments.

What the Net Deficit Impact Looks Like Now

The original CBO and Joint Committee on Taxation score of roughly $143 billion in deficit reduction over 2010 through 2019 assumed every tax provision remained intact, every state expanded Medicaid, and premiums grew at a moderate pace. Later CBO estimates continued to show the coverage provisions roughly paying for themselves through the mid-2010s.¹

That picture has shifted. Repeal of the mandate penalty, the health insurer fee, the medical device tax, and the Cadillac tax collectively removed hundreds of billions in projected revenue. The temporary subsidy expansions under ARPA and the Inflation Reduction Act added spending the original score never contemplated. Silver loading inflated subsidy costs further. The surviving offsets, the Net Investment Income Tax, the Additional Medicare Tax, and Medicare payment reductions, continue producing money. Whether they still fully cover the ACA’s costs depends heavily on the time window and assumptions, and the honest answer is that the law’s net fiscal impact today is far less favorable than the 2010 projection suggested.

The Supreme Court’s 2012 decision in National Federation of Independent Business v. Sebelius also shaped the trajectory by making Medicaid expansion optional for states.⁸ In the short term, that reduced federal spending because fewer people enrolled in expansion Medicaid. Over the longer term, states that initially refused have gradually opted in, spreading the cost across a longer timeline rather than eliminating it.

Where Spending Is Headed for 2026

With the enhanced premium subsidies scheduled to expire after 2025, marketplace subsidy spending is projected to fall from about $140 billion in fiscal year 2025 to roughly $112 billion in fiscal year 2026. The drop reflects the return to the ACA’s original subsidy formula, which caps eligibility at 400% of the federal poverty level and requires higher premium contributions at every income level.²

The subsidy cliff at 400% of poverty means some people who received generous assistance in 2025 face substantially higher premiums in 2026 or drop coverage entirely. How many leave the marketplace, and how that feeds back into premiums and spending in later years, is the main budget uncertainty heading into 2026. If Congress extends the enhanced subsidies again, annual costs stay closer to the $140 billion range. If they revert permanently, gross spending drops, but enrollment does too.

Federal Medicaid expansion payments continue at the 90/10 split in every participating state, with no scheduled changes to that ratio.³ The surviving ACA taxes keep generating revenue and Medicare payment adjustments keep producing savings. But with the Cadillac tax, the health insurer fee, the medical device tax, and the mandate penalty all gone, the revenue side of the ledger has permanent holes that no current legislation fills. The true net cost of Obamacare to the federal government now depends almost entirely on which provisions Congress chooses to extend, restore, or replace.

1
The White House. Official Sources Agree: The Affordable Care Act Reduces the Deficit
2
Office of the Law Revision Counsel. 26 U.S. Code 36B – Refundable Credit for Coverage Under a Qualified Health Plan
3
Medicaid and CHIP Payment and Access Commission. Federal Match Rate Exceptions
4
Office of the Law Revision Counsel. 26 U.S. Code 1411 – Imposition of Tax
5
Office of the Law Revision Counsel. 26 USC 3101 – Rate of Tax
6
Office of the Law Revision Counsel. 26 U.S. Code 4980H – Shared Responsibility for Employers Regarding Health Coverage
7
Internal Revenue Service. Medical Device Excise Tax
8
Justia. National Federation of Independent Business v. Sebelius, 567 U.S. 519 (2012)