What to Do With Leftover HSA Money: Invest, Retire, or Reimburse

Leftover money in your Health Savings Account never expires. The balance rolls over year after year, it belongs to you rather than your employer, and you keep it through job changes, health plan changes, and into retirement.¹ So the real question with leftover HSA money is not whether you’ll lose it, but how to put it to best use: spend it on current medical costs, reimburse yourself for old ones, invest it for tax-free growth, cover certain insurance premiums, or save it for retirement.

Spend It on Qualified Medical Expenses

The most direct use for leftover HSA money is paying current healthcare costs tax-free. Qualified expenses include doctor and hospital visits, prescription drugs, dental work, vision care, and mental health services. The IRS defines the category broadly to cover most costs tied to diagnosing, treating, or preventing a medical condition.²

Since 2020, over-the-counter medications and menstrual products such as tampons, pads, and cups also qualify without a prescription.³ Pain relievers, allergy medicine, and first-aid supplies all count. If you have a balance sitting idle, restocking the medicine cabinet is a legitimate use.

Reimburse Yourself for Past Medical Bills

One of the most valuable features of an HSA is that there is no deadline to reimburse yourself for a qualified expense. You can pay a medical bill out of pocket today, keep the receipt, and withdraw the money from your HSA years or even decades later, tax-free. The only requirement is that your HSA was open before the expense was incurred.¹

This opens up a strategy for people who can afford to cover medical costs from other funds. Leave the HSA money invested, let it compound tax-free, and reimburse yourself when you actually need the cash. It only works if your records hold up. The IRS requires documentation showing that each distribution matched a qualified medical expense that was not reimbursed by insurance or claimed as a tax deduction.¹ Save receipts, explanation-of-benefits statements, and billing records indefinitely.

Invest the Balance for Tax-Free Growth

Most HSA custodians let you invest your balance once you hit a minimum cash threshold, often around $1,000. Above that line, you can typically move money into mutual funds, index funds, bonds, or other options the custodian offers. Available choices and minimums vary, so check with your provider.

The tax treatment inside an HSA is unusually generous. Dividends, interest, and capital gains are all shielded from tax as long as the money stays in the account. There is no annual tax bill on investment growth the way there is in a regular brokerage account. When you eventually withdraw for qualified medical expenses, the distribution, including all the gains, comes out tax-free.⁴

Watch the fees. Custodians commonly charge a monthly maintenance fee of roughly $0 to $2.50, and investment sub-accounts carry their own expense ratios and trading costs. Some employers cover the monthly fee while you work there, and the fee may rise after you leave. You can transfer your HSA to a different provider at any time, so if fees are eroding a smaller balance, shop around.

Cover Certain Insurance Premiums

You generally cannot use HSA funds to pay health insurance premiums, but four exceptions let you pay premiums tax-free:

COBRA continuation coverage after losing employer-based benefits.
Any health plan premium, including marketplace coverage, while you are collecting unemployment compensation.
Medicare Part A, Part B, Part C (Medicare Advantage), and Part D premiums after age 65. Medigap supplement premiums do not qualify.
Long-term care insurance premiums, up to an age-based annual limit.

All four categories allow tax-free distributions.¹

Long-Term Care Premium Limits for 2026

The tax-free amount you can pay from your HSA for long-term care insurance depends on your age at year-end. For 2026:

Age 40 or younger: $500
Age 41 to 50: $930
Age 51 to 60: $1,860
Age 61 to 70: $4,960
Over age 70: $6,200

Premiums paid above these limits with HSA funds are treated as non-medical distributions.

Save It for Retirement After 65

Before age 65, any HSA withdrawal that isn’t for a qualified medical expense triggers ordinary income tax plus a 20 percent additional tax. The additional tax also doesn’t apply if you become disabled.⁴

At 65, the 20 percent penalty goes away. From that point on, your HSA works much like a traditional IRA for non-medical spending: withdraw money for any purpose and pay only ordinary income tax on it.⁴ Someone in the 22 percent bracket would owe 22 percent on a distribution used for travel or housing, and nothing more.

Withdrawals for qualified medical expenses stay completely tax-free after 65, exactly as before. That includes Medicare Part B, Part C, and Part D premiums, plus long-term care premiums up to the age-based limits above. Because healthcare bills tend to climb in retirement, many people find the best tax result comes from keeping HSA money earmarked for medical spending and pulling from other accounts for everything else.

Medicare Enrollment Stops New Contributions

Enrolling in any part of Medicare drops your HSA contribution limit to zero. Spending the existing balance is fine; adding new money is not.¹

There’s a trap that catches people who delay Medicare past 65. When you eventually enroll, Medicare Part A coverage is retroactive up to six months, though never before your 65th birthday. Any HSA contributions you or your employer made during that retroactive window become excess contributions, because you’re treated as having been enrolled in Medicare for those months.¹ Stop HSA contributions at least six months before you plan to enroll.

Applying for Social Security benefits after 65 automatically enrolls you in Medicare Part A, so if you want to keep contributing, you may need to delay both.

What Happens to Leftover Funds When You Die

If your surviving spouse is the named beneficiary, the account simply becomes theirs. It keeps its HSA status, and they can use the funds for their own qualified medical expenses with the same tax-free treatment.⁴

When a non-spouse inherits the account, whether a child, sibling, or friend, the HSA closes on the date of death. The full fair market value is included in the beneficiary’s taxable income for that year.⁴ The taxable amount is reduced by any qualified medical expenses of the deceased that the beneficiary pays within one year of the date of death.¹ If the estate is the beneficiary, the account value goes on the decedent’s final income tax return instead.

To keep leftover money on a tax-favored path, complete a beneficiary designation form with your HSA custodian. Without one, the account usually passes to your estate and may go through probate.

1
Internal Revenue Service. Publication 969 (2025), Health Savings Accounts and Other Tax-Favored Health Plans
2
Office of the Law Revision Counsel. 26 USC 213 – Medical, Dental, Etc., Expenses
3
Internal Revenue Service. IRS Outlines Changes to Health Care Spending Available Under CARES Act
4
Office of the Law Revision Counsel. 26 USC 223 – Health Savings Accounts