ACA premium subsidy,
the exact 2026 math.

Field guide

How the 2026 ACA premium subsidy is actually calculated.

The core formula (26 U.S.C. §36B) is simple to state and easy to get wrong in the details: your monthly premium tax credit equals your area's benchmark plan premium minus your expected monthly contribution, where the expected contribution is your household income times an "applicable percentage" that rises as your income rises. For 2026, both halves of that equation reverted to less generous, pre-2021 rules.

The applicable-percentage table, exactly as published

IRS Revenue Procedure 2025-25 sets the 2026 applicable percentages precisely, and this calculator uses those exact figures rather than a rounded approximation:

• Under 133% FPL: a flat 2.10%
• 133%–150% FPL: rises linearly from 3.14% to 4.19%
• 150%–200% FPL: rises linearly from 4.19% to 6.60%
• 200%–250% FPL: rises linearly from 6.60% to 8.44%
• 250%–300% FPL: rises linearly from 8.44% to 9.96%
• 300%–400% FPL: a flat 9.96%
• Over 400% FPL: no credit at all

Notice the real jump right at 133% FPL — from a flat 2.10% to 3.14% — rather than a smooth continuation. That's not rounding or an error in this calculator; it's exactly how the IRS table is published. Within each band above that point, the percentage moves in a straight line: a household at 225% FPL, exactly the midpoint of the 200–250% band, gets exactly the midpoint percentage, 7.52%.

The one-year FPL lag

2026 Marketplace coverage is measured against the 2025 federal poverty guidelines, not a 2026 table — because eligibility for a coverage year is pinned to whatever FPL guidelines were most recently published as of the start of that year's open enrollment period, which happens before the new calendar year's guidelines are released (26 CFR §1.36B-1(h)). Alaska and Hawaii have their own, separately higher poverty guidelines — using the 48-state numbers for a household in either state would understate their real eligibility and subsidy amount.

Your household's actual 400% cliff, in dollars

"400% of the poverty line" isn't a single number — it depends on your household size and which of the three FPL tables applies to you. For the 48 contiguous states and DC using 2025 guidelines, 400% FPL is $62,600 for one person and $128,600 for a family of four; Alaska's and Hawaii's higher guidelines push those numbers higher still. This calculator computes your household's own cliff amount directly rather than quoting a single generic figure.

The credit's real ceiling: your actual premium

One detail simplified subsidy estimates often skip: your credit can never exceed what you're actually being charged for the plan you enroll in. If you choose a plan cheaper than the benchmark Silver plan, your credit is capped at that lower premium — you can't receive more credit than your actual monthly bill. This calculator models that cap explicitly via an optional "actual plan premium" field.

2026's highest-stakes change: no more repayment cap

If you take your credit in advance and your actual income for the year ends up higher than what you estimated at enrollment, you have to repay the difference. Through 2025, a repayment cap limited how much of that excess a household under 400% FPL had to pay back — as little as a few hundred dollars in the lowest income tier. That cap is gone for 2026 coverage: you now owe back the entire excess advance credit, no matter your income level. Because self-employed and freelance income is notoriously hard to estimate accurately a year in advance, this change disproportionately affects exactly the households most likely to use ACA Marketplace coverage in the first place.

Disclaimer

This calculator is for informational planning purposes only and does not constitute tax or insurance advice. It does not model employer-sponsored coverage affordability, special enrollment rules, or state-specific Marketplace variations. Your benchmark premium must be looked up directly through healthcare.gov or your state exchange — confirm your actual eligibility and credit amount with the Marketplace or a licensed tax professional before making enrollment decisions.