ACA Premium Tax Credit Calculator: Subsidy and 400% Cliff

The premium tax credit lowers the monthly cost of a health plan bought through HealthCare.gov or your state's marketplace. Enter your household size, expected income and the benchmark silver premium, and this calculator applies the IRS formula for 2026 or 2027 coverage. It shows your credit, what you pay each month, and how far your income is from the 400% poverty-line cliff.

The short answer: your credit equals the monthly premium of the benchmark plan (the second-lowest-cost silver plan where you live) minus a set share of your household income. That share runs from 2.10% to 9.96% for 2026 coverage (Rev. Proc. 2025-25) and from 2.15% to 10.22% for 2027 coverage (Rev. Proc. 2026-26). The credit only goes to households with income from 100% to 400% of the federal poverty line. Above 400% there is no credit at all, and from 2026 any advance credit you received but didn't qualify for is repaid in full (IRS Pub. 505).

The calculator is for informational purposes only, and its results are estimates. The marketplace application decides your advance credit, and Form 8962 on your tax return sets the final amount. Both use your actual premiums, monthly enrollment and final household income, which this tool can only approximate.

How is the ACA premium tax credit calculated?

The credit is set by 26 U.S.C. §36B and computed on Form 8962. The calculator follows the form's steps:

1. Find your poverty line. The credit uses the HHS poverty guidelines in effect on the first day of open enrollment (26 CFR 1.36B-1(h)). That means the previous year's guidelines. For 2026 coverage that is the 2025 table: $15,650 for one person plus $5,500 for each additional person in the 48 contiguous states and DC (90 FR 5917). For 2027 coverage it is the 2026 table: $15,960 plus $5,680 per person (91 FR 1797).
2. Express household income as a percentage of that line. Divide income by the poverty line, multiply by 100, and drop the decimals. Above 400%, the form enters 401 and you stop (Instructions for Form 8962).
3. Look up your applicable percentage. Within each income band of the IRS table, the percentage rises in a straight line from the band's starting rate to its ending rate. The IRS rounds the result to four decimals (for example 0.0663).
4. Multiply income by that percentage. This is your expected contribution for the year, rounded to the dollar (Form 8962 line 8a). Divide by 12 and round again for the monthly figure (line 8b).
5. Subtract it from the benchmark premium. The monthly credit is the benchmark premium minus your monthly contribution. It can't be more than the premium of the plan you actually enroll in, and it can't go below zero.

When your premiums and household are the same all year, Form 8962 lets you use annual totals on line 11. That can differ from 12 × the monthly credit by a few dollars of rounding, and the calculator uses the annual method for 12 months of coverage.

Applicable percentage table for 2026 and 2027

This is the share of household income you are expected to pay toward the benchmark plan. In each band, the first number applies at the bottom and the second at the top.

Sources: Rev. Proc. 2025-25, section 3.01, and Rev. Proc. 2026-26, section 3.01. Both say the extra indexing adjustment in §36B(b)(3)(A)(ii)(II) does not apply for those years.

For comparison, the enhanced table in effect for 2021 through 2025 charged 0% up to 150% of the poverty line and capped everyone at 8.5% with no upper income limit (§36B(b)(3)(A)(iii)). That provision applies only to tax years beginning before January 1, 2026. As of October 2026, Congress has not extended it.

The 400% subsidy cliff: income limits by household size

The statute defines an "applicable taxpayer" as a household whose income is at least 100% and not more than 400% of the poverty line (§36B(c)(1)(A)). Above 400%, the credit doesn't shrink gradually. It disappears for the entire year.

These figures are 4 × the poverty guideline for the 48 contiguous states and DC. Alaska and Hawaii have their own, higher guidelines. For one person in Alaska, the 400% line is $78,200 for 2026 coverage and $79,800 for 2027. In Hawaii it is $71,960 and $73,440.

Worked example: a couple at the cliff

A couple (household of two) buys 2026 coverage. Their benchmark silver premium is $1,400 a month, or $16,800 a year.

• Household income of $84,600 is exactly 400% of $21,150. The applicable percentage is 9.96%.
• Expected contribution: $84,600 × 0.0996 = $8,426.16, rounded to $8,426.
• Credit: $16,800 − $8,426 = $8,374 for the year, about $698 a month.
• At $84,601 of income they are over 400%. The credit drops to $0, and the plan costs the full $16,800.

So one extra dollar of income costs $8,374 of credit. At $90,000 of income they are $5,400 over the line. If neither spouse is covered by a workplace retirement plan, deductible traditional IRA contributions totaling $5,400 would bring household income back to $84,600. The 2026 IRA limit is $7,500 per person, so that fits within the limit. A bronze marketplace plan also counts as HSA-compatible starting in 2026 (IRS Notice 2026-5), and HSA contributions reduce AGI as well.

The MAGI calculator shows the ACA version of your modified AGI next to the Roth and IRMAA versions. The HSA calculator shows how much a contribution would save.

Worked example: one person, 2027 coverage

A single person expects $45,000 of household income in 2027 and lives in one of the 48 contiguous states. The benchmark silver plan costs $650 a month.

1. Poverty line (2026 guidelines, used for 2027 coverage): $15,960.
2. $45,000 ÷ $15,960 = 2.8195, so household income is 281% of the poverty line.
3. 281% falls in the 250%–300% band, which runs from 8.66% to 10.22%. The applicable percentage is 8.66% + (10.22% − 8.66%) × 31 ÷ 50 = 9.6272%, rounded to 9.63%.
4. Expected contribution: $45,000 × 0.0963 = $4,333.50, rounded to $4,334 a year. Divided by 12, that's $361 a month.
5. Credit: $650 − $361 = $289 a month. On an annual basis it's $7,800 − $4,334 = $3,466.

If this person picks the benchmark plan, they pay $361 a month. If they pick a $480 bronze plan, the $289 credit still applies and they pay $191. The same income and premium for 2026 coverage gives a slightly larger credit, $3,498 for the year. The 2026 table charges 9.56% at 287% of the 2025 poverty line.

Worked example: a family of four choosing bronze

A family of four expects $50,000 of household income for 2026 coverage. Their benchmark silver plan is $1,800 a month, and they choose a bronze plan at $1,200.

• Poverty line: $15,650 + 3 × $5,500 = $32,150. $50,000 ÷ $32,150 = 1.555, so 155%.
• Applicable percentage: 4.19% + (6.60% − 4.19%) × 5 ÷ 50 = 4.43%.
• Expected contribution: $50,000 × 0.0443 = $2,215 a year, $185 a month.
• Benchmark minus contribution: $1,800 − $185 = $1,615. That's more than the $1,200 bronze premium, so the credit is capped at $1,200 a month. The family pays $0 in premiums.

A family at this income should also compare silver plans. Households up to 250% of the poverty line can get cost-sharing reductions, which raise the plan's share of covered costs to as much as 94% (42 U.S.C. §18071). That lowers deductibles and copays, but only on a silver plan (HealthCare.gov).

What you repay at tax time (no cap from 2026)

The marketplace pays the credit to your insurer each month based on your income estimate. When you file, Form 8962 compares those advance payments with the credit your actual income supports.

Before 2026, the repayment for households under 400% was capped. For 2025 the caps ran from $375 (single, under 200%) to $3,250 (other filers, 300%–400%), according to Table 5 of the 2025 Form 8962 instructions. The One Big Beautiful Bill Act removed that limit for tax years after 2025 (Pub. L. 119-21 §71305). Pub. 505 now says there is no limit on what you pay back, "even if your household income is less than 400% of the federal poverty line."

Example: a single person estimated 2026 income at $31,300 (200%) with a $500 benchmark premium. The marketplace paid $328 a month in advance credit, $3,936 for the year. Their actual income turned out to be $40,000:

• $40,000 ÷ $15,650 = 255% → applicable percentage 8.44% + 1.52% × 5 ÷ 50 = 8.59%.
• Contribution: $40,000 × 0.0859 = $3,436. Credit: $6,000 − $3,436 = $2,564.
• Repayment: $3,936 − $2,564 = $1,372, added to the tax on the return in full.

Enter your monthly advance credit in the calculator's optional field to run this check for your own numbers. If your income changes mid-year, report it to the marketplace so the advance credit is adjusted (HealthCare.gov). You can also choose to take less of the credit in advance and claim the rest on your return.

The calculator's inputs explained

• Coverage year. 2026 uses Rev. Proc. 2025-25 and the 2025 guidelines. 2027 uses Rev. Proc. 2026-26 and the 2026 guidelines.
• Where you live. Alaska and Hawaii have their own poverty guidelines. Everyone else uses the contiguous-states figures.
• Household size. Count yourself, your spouse, and everyone you will claim as a dependent, even if they don't need coverage. Married couples generally must file jointly to claim the credit (§36B(c)(1)(C)). Married filing separately disqualifies you unless you meet the domestic-abuse or abandonment exception in the Form 8962 instructions.
• Household income. Use the modified AGI of everyone in the household who is required to file. That's AGI plus tax-exempt interest, Social Security benefits that aren't taxed, and excluded foreign income (HealthCare.gov). It is an estimate of the coverage year's income, not last year's. Our guide to what MAGI is walks through each add-back.
• Benchmark premium. This is the full monthly price of the second-lowest-cost silver plan for the people you enroll, which is what Form 1095-A column B reports. Premiums vary by age, county and tobacco use, so get the figure from the marketplace's plan preview rather than guessing.
• Plan premium. This is the full price of the plan you choose. If it's below the benchmark minus your contribution, the credit is limited to it.
• Months. This is how many months you have marketplace coverage. For part-year coverage, the calculator uses the monthly lines of Form 8962.
• Advance credit. This optional field takes the monthly advance credit from your eligibility notice or Form 1095-A column C. With it, the calculator estimates your repayment or extra refund.

Who can't get the credit

• Income below 100% of the poverty line. In states that expanded Medicaid, adults up to 138% of the poverty line generally qualify for Medicaid instead (HealthCare.gov). If the marketplace estimated your income at 100%–400% and paid advance credit, you can generally still claim the credit even if your actual income ends up below 100% (26 CFR 1.36B-2(b)(6)). In that case, enter the advance credit in the calculator: it figures your credit on your actual income at the lowest rate in the table. The old exception for lawfully present immigrants under 100% was repealed for 2026 and later (Pub. L. 119-21 §71302).
• People offered affordable employer coverage. Employer coverage blocks the credit if it costs no more than the required contribution percentage of household income and the plan meets minimum value. For the employee, the test uses the cost of employee-only coverage. For a spouse and dependents, it uses the cost of family coverage (26 CFR 1.36B-2(c)(3)(v)). That percentage is 9.96% for 2026 plan years and 10.22% for 2027 (section 3.02 of each Rev. Proc.).
• Anyone who can be claimed as a dependent by someone else (§36B(c)(1)(D)).
• Some lawfully present immigrants, starting in 2027. For tax years after 2026, only lawful permanent residents, Cuban and Haitian entrants, and people living in the U.S. under a Compact of Free Association count as eligible for the credit (Pub. L. 119-21 §71301, amending §36B(e)).

Common mistakes and edge cases

• Forgetting dependents' income. A dependent who is required to file adds their MAGI to household income, even if they don't need coverage.
• Leaving out untaxed Social Security. Early retirees on Social Security often add only the taxable portion. The credit counts the untaxed portion too.
• Doing a Roth conversion or selling stock without checking the cliff. Conversions and capital gains raise household income. The Roth conversion calculator shows the tax side, and this tool shows what the extra income does to the credit.
• Self-employment income. The self-employed health insurance deduction lowers AGI, and that AGI in turn affects the credit. Pub. 974 has an iterative method for this (IRS Pub. 974). For a first estimate, enter your expected net profit after the deduction. The 1099 tax guide covers the rest of a freelancer's tax bill.
• Moving between Alaska or Hawaii and another state. The higher poverty guideline applies for the year (26 CFR 1.36B-1(h)).
• Open enrollment dates. On HealthCare.gov, open enrollment for 2027 coverage runs from November 1 through January 15. Enroll by December 15 for coverage that starts January 1 (HealthCare.gov). State-run marketplaces can set different dates.

Related calculators and guides

Planning a gap between jobs or an early retirement? A year with little earned income can put you deep inside the credit's range. The career break calculator estimates what the break costs in lifetime earnings, retirement savings and Social Security, so you can weigh that against a lower premium. For everything that changed on 2026 returns, including the end of the repayment cap, see the 2026 tax changes guide. The income tax basics hub collects the rest of our federal tax calculators.