What Happens If You Contribute to an HSA Without an HDHP?

If you contributed to a Health Savings Account without a qualifying high-deductible health plan, the IRS treats the deposit as an excess contribution: you lose the tax deduction, and a 6% excise tax applies to the ineligible amount for every year it stays in the account. The fix is straightforward if you catch it in time. Pull the money (and any earnings it generated) out of the HSA before your tax filing deadline, and the 6% excise tax never applies.¹

When a Contribution Counts as Ineligible

You qualify to contribute to an HSA only during months when, on the first day of the month, you carry a qualifying HDHP, have no disqualifying additional coverage, are not enrolled in Medicare, and are not claimed as a dependent on someone else’s return.² Miss any one of those for a given month and your eligible contribution for that month is zero.

A few disqualifiers catch people off guard. A general-purpose Flexible Spending Account through your employer or a spouse’s employer counts as disqualifying coverage. TRICARE does too, since the Department of Defense does not classify it as an HDHP.³ Limited-purpose FSAs restricted to dental and vision are the exception and don’t disqualify you.

Medicare is the trap for people working past 65. When you enroll in Part A after 65, coverage applies retroactively for up to six months before the enrollment date. Any HSA contributions you made during those retroactive months turn into excess contributions. If you want to keep contributing past 65, stop at least six months before enrolling in Medicare or claiming Social Security, which triggers automatic Part A enrollment.²

The same rules apply if you were otherwise eligible but overshot the annual limit. For 2026, that limit is $4,400 for self-only HDHP coverage and $8,750 for family coverage, with an extra $1,000 catch-up for anyone 55 or older.⁴ The limit is prorated by month, so partial-year HDHP coverage means a partial-year cap.

What the Penalty Actually Costs

Two things happen to an ineligible contribution. You can’t deduct it, and if your employer put the money in pretax through payroll, the amount is added back to your gross income.² Then the IRS layers on a 6% excise tax on whatever excess sits in the account at the end of the tax year.⁵

The 6% is not a one-time hit. It repeats every year the excess remains. A $5,000 ineligible contribution costs you $300 the first year, another $300 the second, and so on until you remove the money or absorb it against a future year’s contribution room. You report and pay the excise tax on Form 5329.² The tax is capped at 6% of the year-end account value, which rarely matters in practice but prevents the penalty from exceeding the balance.⁵

Fixing It Before Your Tax Deadline

The cheapest correction is a withdrawal before the due date of your tax return, including extensions. That window usually runs through April 15 of the following year, later if you filed for an extension.¹ Pull the money out in time and the 6% excise never applies.

Call your HSA custodian and ask for a “return of excess contribution.” You need to withdraw both the excess principal and any earnings that money generated while it sat in the account. The custodian calculates those attributable earnings and reports the distribution on Form 1099-SA using distribution code 2.⁶

The principal itself isn’t taxed when it comes back out, because you already lost the deduction or had the pretax amount added back to income. The earnings are taxable as ordinary income in the year you receive them, but they escape the 20% additional tax that normally hits non-qualified HSA withdrawals, provided you follow the correction procedure.⁷

File Form 8889 with your return for the contribution year to report the excess and its withdrawal.⁸ A timely correction costs you nothing beyond income tax on whatever modest earnings the excess threw off.

The Six-Month Extended Window

If you filed on time but forgot to pull the excess out first, there is still a backup. The IRS gives you up to six months after the original due date of your return (not counting extensions) to make the withdrawal. To use it, file an amended return with “Filed pursuant to section 301.9100-2” written at the top, explain the withdrawal, and include an amended Form 5329 showing the amount is no longer treated as excess.¹

Fixing It After You’ve Missed the Window

Once both the filing deadline and the six-month extension are gone, the 6% excise tax for the contribution year is locked in. Pay it by filing Form 5329 for that year. If you originally deducted the ineligible contribution on your return, file an amended Form 1040-X to add the amount back to gross income.¹

The 6% continues to apply each subsequent year the excess remains in the account at year-end. Withdrawing the money now stops future excise taxes but doesn’t erase what you already owe for closed years.

Absorbing the Excess in a Future Year

If you expect to be HSA-eligible again soon, you can leave the excess in the account and absorb it by under-contributing in a later year. The amount you can deduct in that new year equals the lesser of your remaining contribution room (annual limit minus current-year contributions) or the total prior-year excess still in the account.² Once absorbed, the 6% stops. You still owe the excise for each intervening year, so this path only works out if the regained eligibility is close.

If the excess came in through payroll, loop in your employer’s benefits department. The contribution may need to be returned directly to the employer, and depending on timing, the employer may issue a corrected W-2 reflecting the added gross income. Which tax year the income lands in depends on when the return happens, so coordinate the custodian and the employer together.

The HSA Itself Still Works Without an HDHP

Losing HDHP coverage affects only your ability to contribute. The existing balance stays yours. You can withdraw at any time and spend tax-free on qualified medical expenses, regardless of your current health plan.² The account stays open, investments keep growing tax-free, and nothing changes about how qualified withdrawals are taxed.

Non-medical withdrawals are a different matter. They go into gross income and carry a 20% additional tax.⁹ The 20% drops away at age 65 or on disability, though the income tax still applies.

A State Tax Note

A few states with income taxes don’t recognize the federal HSA deduction. California and New Jersey are the most notable: residents owe state income tax on HSA contributions regardless of federal treatment. An excess contribution corrected federally may still need separate handling on your state return. If you file in one of those states, check with your state tax authority or a tax professional to confirm what to report.

1
Internal Revenue Service. Instructions for Form 8889 (2025)
2
Internal Revenue Service. Publication 969 (2025), Health Savings Accounts and Other Tax-Favored Health Plans
3
TRICARE. Do Health Savings Accounts Work With TRICARE?
4
Internal Revenue Service. Rev. Proc. 2025-19
5
Office of the Law Revision Counsel. 26 U.S. Code 4973 – Tax on Excess Contributions to Certain Tax-Favored Accounts
6
Internal Revenue Service. Instructions for Forms 1099-SA and 5498-SA (Rev. December 2026)
7
Internal Revenue Service. Instructions for Form 5329 (2025)
8
Internal Revenue Service. About Form 8889, Health Savings Accounts (HSAs)
9
Office of the Law Revision Counsel. 26 U.S. Code 223 – Health Savings Accounts