Health & Medicare
How the ACA Health Insurance Subsidy Actually Works
Based on IRS Revenue Procedure 2025-25 and the 2025 HHS poverty guidelines used for 2026 coverage, updated August 2026.
The premium tax credit is not a percentage-off coupon. It is the gap between what a benchmark plan costs and what your income says you can afford. Here is exactly how that gap gets calculated for 2026.
Data sourced from IRS Revenue Procedure 2025-25, HHS/ASPE Poverty Guidelines, KFF
Two numbers decide your credit, not one
The premium tax credit (PTC) comes from comparing exactly two figures. The first is the cost of the "benchmark plan," the second-lowest-cost Silver plan available where you live, at your age.
The second is your "expected contribution," the amount the government thinks your household can reasonably put toward coverage, set as a sliding percentage of your income. Your credit is the difference: benchmark premium minus expected contribution. If your expected contribution already covers or exceeds the benchmark cost, the credit is $0.
That structure matters because it means the credit is not really about the plan you buy. It is about the gap between a reference price and your income.
Buy a cheaper plan than the benchmark and you pocket the difference; buy a pricier one and you pay the difference yourself. The credit dollar amount does not change either way, only your out-of-pocket premium does.
2026 is a smaller subsidy than the last five years
From 2021 through 2025, this formula was temporarily much more generous. The American Rescue Plan Act removed the income cliff entirely and capped every household's expected contribution at 8.5% of income no matter how high their earnings were, and the Inflation Reduction Act extended that arrangement through the end of 2025.
Both changes had a fixed expiration date. Despite active debate in Congress through late 2025, no extension passed before the deadline, so 2026 marketplace coverage reverts to the original, pre-2021 ACA rules: a hard cliff at 400% of the federal poverty level (FPL), and expected-contribution percentages that run from 2.10% of income at the low end up to a flat 9.96% for anyone between 300% and 400% FPL, both noticeably steeper than what 2025 enrollees paid.
A worked example
Take a single applicant earning $30,000 a year, which works out to roughly 192% of the federal poverty level for a household of one. That lands inside the 150-200% FPL band, where the expected contribution rate is 6.2% of income, or about $1,860 a year toward coverage.
Against a national average benchmark premium of $625 a month ($7,500 a year), that leaves a credit of roughly $5,640 a year, about $470 a month, well over 80% of the benchmark premium covered by the subsidy alone.
Real benchmark premiums vary a lot by state, from the low $300s a month in Washington, D.C. to well over $1,000 a month in states like Wyoming and West Virginia, so treat the figure above as an illustration of the mechanics, not a stand-in for your own state's number.
Why age moves the number, and income doesn't (directly)
Age affects only one side of the equation: the benchmark premium. ACA plans use a federally standardized age curve, where a 64-year-old's premium can run up to 3 times a 21-year-old's for identical coverage.
Holding income and household size constant from the example above, a 25-year-old's benchmark premium comes out to about $5,892 a year, producing a credit of about $4,032. A 60-year-old at the exact same income sees a benchmark premium of about $15,927 a year, and because the expected contribution does not change with age, a larger credit of roughly $14,067.
Older applicants are not penalized by the subsidy formula, the higher premium they are quoted in the first place is what drives the bigger dollar credit.
The cliff at the top, in brief
One consequence of this formula deserves its own explanation rather than a quick mention here: crossing 400% of the federal poverty level does not gradually shrink your credit toward zero, it eliminates it entirely, in one step, no matter how small the overage.
See how the subsidy cliff actually works for the mechanics of that specific edge case, including how close to the line is close enough to matter.
Frequently asked questions
What income makes me eligible for a premium tax credit?
Generally, household income from 100% up to 400% of the federal poverty level (FPL), based on the prior year's HHS poverty guidelines. Below 100% FPL, marketplace credits typically do not apply since most people in that range qualify for Medicaid instead in states that expanded it.
At or above 400% FPL, the federal credit drops to exactly $0, a hard line commonly called the subsidy cliff.
Is the premium tax credit the same as it was in 2021 through 2025?
No. The enhanced credits created by the American Rescue Plan Act and extended by the Inflation Reduction Act removed the 400% FPL cliff and capped everyone's contribution at 8.5% of income.
Those enhancements expired December 31, 2025, and Congress did not extend them, so 2026 coverage uses the original, less generous ACA formula: a hard cliff at 400% FPL and steeper required-contribution percentages.
Why does my age change the size of my credit?
Because the credit is the gap between your area's benchmark plan premium and your expected contribution, and only the benchmark premium side moves with age. ACA plans are priced on a federal age curve that charges older enrollees up to 3 times what a 21-year-old pays for the same plan, so a higher benchmark premium at an older age generally produces a larger credit at identical income, not a smaller one.
Do I have to buy the benchmark plan to get the credit?
No. The benchmark plan (the second-lowest-cost Silver plan in your area) is only the reference point the credit formula uses. Once your dollar credit is calculated, you can apply it to any metal-tier plan sold on the marketplace.
A plan priced below the benchmark lowers your net cost further; a pricier plan raises it.