ACA subsidy calculator for 2026 coverage

By Tom, CPA · Updated October 25, 2026

TL;DR: Enter household size, expected MAGI and your benchmark silver premium. The calculator applies the 2026 poverty line and the IRS applicable percentage table to estimate your premium tax credit, and shows how much income room you have before the 400% cliff.

Educational only, not tax, legal, or investment advice. Examples are illustrations, not predictions. Rules and limits change; verify current figures and talk to a qualified professional about your situation.

Estimate your subsidy before the marketplace does it for you. With the enhanced credits expired at the end of 2025 and not extended as of Oct 2026, the 400% of poverty cliff is back for 2026 coverage. Small changes in income can now mean thousands of dollars of difference. This calculator uses the official numbers so you can test conversions, capital gains and other decisions before you make them.

CPA Warning Label: This calculator is a flashlight, not a tax return. Your marketplace application and Form 8962 have the final word.

Inputs

• Household size. Generally you, your spouse if filing jointly, and anyone you claim as a dependent.
• Expected MAGI. Adjusted gross income plus tax-exempt interest, non-taxable Social Security and excluded foreign income. See ACA MAGI management for what counts.
• Benchmark premium. The full annual price of the second-lowest-cost silver plan for your household in your area. Find it by previewing plans on HealthCare.gov or your state marketplace; it depends on ages and ZIP code, so the calculator can't guess it.

The calculator uses the lower-48 poverty guideline. Alaska and Hawaii use higher guidelines, so results there will be off.

FPL and applicable percentage

For 2026 coverage, the marketplace uses the 2025 federal poverty guidelines: $15,650 for one person plus $5,500 for each additional person (so $21,150 for two and $32,150 for four). Your income as a percentage of that figure picks a row on the IRS table from Revenue Procedure 2025-25:

Within each band, the percentage rises in a straight line. Multiply it by MAGI to get your expected contribution toward the benchmark plan.

Benchmark premium input

Your credit equals the benchmark premium minus your expected contribution, if positive. You can apply it to any metal-level plan. If you pick a cheaper bronze plan, your net premium may be very low; if you pick gold, you pay the difference. The credit can't exceed the premium of the plan you actually buy.

Benchmarks often rise sharply with age, which is why early retirees in their 60s can receive large credits even at moderate incomes.

Cliff warning

Above 400% of FPL, the credit is zero for 2026 coverage. The "income room before the cliff" output shows how many dollars of MAGI you can add before crossing it. Also, for tax years after 2025, the caps that used to limit repayment of excess advance credits no longer apply, so overshooting can mean repaying everything. Leave a buffer, and see the subsidy cliff guide and premium tax credit reconciliation.

Below 100% of FPL, the calculator shows no credit, because you generally won't get marketplace savings there; in expansion states you may qualify for Medicaid below 138%. See the Medicaid gap.

Examples

Illustration: a couple with MAGI of $60,000 and an $18,000 benchmark: 283.7% of FPL, applicable percentage 9.46%, expected contribution about $5,678, credit about $12,322 a year, about $1,027 a month. They have $24,600 of room before the cliff.

Same couple at $84,601: just over 400%, so the credit is $0. One dollar costs about $9,574 compared with sitting exactly at $84,600.

A single person with MAGI of $45,000 and a $9,000 benchmark: 287.5% of FPL, applicable percentage about 9.58%, credit about $4,688.

A single person with MAGI of $19,000 and an $8,400 benchmark: 121.4% of FPL, applicable percentage 2.10%, credit about $8,001, unless they're in an expansion state and Medicaid-eligible.

Limitations

• Doesn't model cost-sharing reductions; see cost-sharing reductions.
• Doesn't model affordable employer coverage offers, which can block the credit.
• Uses 2026 coverage rules as of Oct 2026. Rules for 2027 will use the 2026 poverty guidelines and new IRS percentages.
• Ignores Alaska and Hawaii guidelines.

How to use the results

Run the calculator at several MAGI levels: your baseline, your baseline plus a planned Roth conversion, and a pessimistic case with extra capital gain distributions. The difference in credits between runs is the hidden "tax" on that extra income. Compare it with the income tax you'd pay. If a $10,000 conversion costs $1,200 in income tax and another $900 in lost credit, your true marginal rate is 21%, not 12%. That's the number to use when deciding how much to convert.

Then enter your estimate on the marketplace application. If income changes during the year, update it, so your advance credits track reality.