If you owe taxes because of health insurance, the reason is almost always the same: the advance premium tax credit the marketplace paid to your insurer during the year turned out to be larger than what your final income actually qualified you for, and the IRS wants the difference back when you file. That reconciliation happens on Form 8962, and for the 2026 tax year the math is harsher than it has been in five years because the enhanced subsidies expired, the 400% income cliff returned, and the caps that used to limit how much you had to repay are gone.
How the Advance Credit Turns Into a Tax Bill
When you enrolled in a marketplace plan, you estimated your household income for the year. The marketplace used that estimate to calculate a monthly subsidy and paid it directly to your insurer, lowering the premium you saw on your bill. At tax time, the IRS recalculates the credit using the income you actually earned. Two outcomes are possible. If you received too little, the extra credit gets added to your refund. If you received too much, the excess is added to your tax bill, which is why an expected refund can shrink, disappear, or flip into a balance due.1Internal Revenue Service. Reconciling Your Advance Payments of the Premium Tax Credit
Every taxpayer who received advance payments has to file Form 8962 with their return. To fill it out you need Form 1095-A from your marketplace, which arrives by late January and lists your monthly premiums, the second-lowest-cost silver plan (SLCSP) figure for your area, and the advance credit paid on your behalf.2Internal Revenue Service. Health Insurance Marketplace Statements Check every line. A wrong premium, a wrong SLCSP, or advance-payment totals that don’t match IRS records will produce either a delayed refund or a bill you didn’t expect. If something looks off, contact the marketplace for a corrected 1095-A before you file.
What Changed for 2026
Two policy changes explain why 2026 bills are bigger than what people got used to during the enhanced-subsidy years.
The 400% Income Cliff Is Back
From 2021 through 2025, enrollees earning above 400% of the federal poverty level could still receive a partial credit. Those enhancements expired on January 1, 2026.3Congress.gov. Enhanced Premium Tax Credit and 2026 Exchange Premiums4Internal Revenue Service. Eligibility for the Premium Tax Credit5HHS ASPE. 2026 Poverty Guidelines: 48 Contiguous States Someone who estimated $60,000 at enrollment but earned $65,000 owes back every dollar of advance credit received during the year.
No More Repayment Caps
Before 2026, the IRS capped repayment for lower-income households so a modest income miscalculation didn’t produce a four-figure tax bill. Starting with the 2026 tax year, those caps are gone. You repay the full difference between what your insurer received and what you qualified for, regardless of income.6Internal Revenue Service. Updates to Questions and Answers about the Premium Tax Credit (FS-2025-10)
Expected Contribution Percentages Went Up
The share of income you’re expected to pay toward the benchmark silver plan also rose. For 2026, applicable percentages run from 2.10% at the low end of the eligibility range to 9.96% at the top.7Internal Revenue Service. Rev. Proc. 2025-25 These are higher than the enhanced rates that applied through 2025. Even if your income came in exactly where you predicted, your credit for 2026 is probably smaller than the one you reconciled last year.
Why Your Actual Income May Have Beat Your Estimate
The income figure that drives your credit is modified adjusted gross income, which is your AGI plus untaxed foreign income, non-taxable Social Security benefits, and tax-exempt interest.8HealthCare.gov. Modified Adjusted Gross Income (MAGI) MAGI is broader than the wages on your paycheck. A side gig, a capital gain, a bonus, or a spouse picking up extra hours can push it above what you told the marketplace at enrollment.
Life changes hit the same way. Getting married combines two incomes on one return. A child leaving the household changes your family size and your FPL percentage. A raise mid-year raises your annual total even if your monthly paycheck only jumped for the last quarter. Any of these events, unreported to the marketplace, will show up as a reconciliation gap at filing.
The Self-Employment Wrinkle
Self-employed enrollees face a circular calculation. The self-employed health insurance deduction reduces AGI and therefore MAGI, but MAGI determines the premium tax credit, which determines how much premium you actually paid after subsidy, which determines the deduction. The IRS requires an iterative calculation to solve this, and Publication 974 walks through it. Two additional rules trip people up: the deduction cannot exceed net self-employment income from the business the plan is established under, and you cannot claim it for any month you were eligible for a subsidized employer plan, including one offered through a spouse.9Internal Revenue Service. Instructions for Form 7206
When Employer Coverage Disqualifies You Retroactively
If your employer offered a plan that met both the minimum value test (covering at least 60% of expected costs) and the affordability test (employee share of the premium at or below 9.96% of household income for 2026), you generally cannot receive marketplace credits at all.10Internal Revenue Service. Minimum Value and Affordability7Internal Revenue Service. Rev. Proc. 2025-25 If you took subsidies anyway, you owe them back.
Individual coverage HRAs (ICHRAs) trigger the same analysis. If the ICHRA your employer offered would have made your self-only lowest-cost silver plan affordable, you cannot receive premium tax credits even if you turned the ICHRA down.11HealthCare.gov. Individual Coverage Health Reimbursement Arrangements (HRAs) A taxable health stipend is different. It shows up as wages on your W-2, gets taxed like any other income, and inflates your MAGI. If you didn’t include that stipend in the estimate you gave the marketplace, it can quietly push you above the credit you were paid on.
State Mandate Penalties Are a Separate Line
The federal penalty for going without coverage dropped to zero in 2019, so a coverage gap does not by itself produce a federal tax bill.12HealthCare.gov. Exemptions from the Fee for Not Having Coverage Several states and the District of Columbia still assess their own mandate penalties through the state return, typically a flat dollar amount per uninsured adult or a percentage of household income, whichever is higher. If you live in one of those states and had a coverage gap, expect that charge on your state return, not your federal one.
What to Do Now, and Next Year
If you already received the bill, file Form 8962 with your return using the numbers on your 1095-A. Skipping it isn’t an option: the IRS will send a Letter 12C asking for the missing form, and if you fail to file and reconcile for two consecutive years the marketplace can cut off your advance credit going forward, which means paying the full unsubsidized premium every month and waiting to claim any credit as a lump sum at filing.13CMS. What Does Failure to File and Reconcile Mean?
For next year, the practical fix is reporting income and household changes to the marketplace when they happen rather than at tax time. A raise, a new job, a marriage, a birth, or someone leaving the household all move your credit. Updating the marketplace lets the system adjust your monthly advance payment in real time, so the gap you reconcile against in April stays small. Given that 2026 removed both the 400% cushion and the repayment caps, the cost of leaving a stale estimate in place is higher than it used to be.