What Happens If You Don’t Use HSA Money? Rollover, Investing, and Age 65

If you don’t use the money in your HSA, nothing happens to it — the balance rolls over year after year, stays yours for life, and keeps earning interest or investment returns until you decide to spend it. Federal tax law treats your Health Savings Account balance as nonforfeitable, so no employer, plan administrator, or calendar deadline can take it away.¹ Unused HSA funds never expire, and after age 65 you can withdraw them for any purpose without penalty.

Unused HSA Funds Roll Over Indefinitely

Whatever you don’t spend this year sits in the account next year. The year after that, same thing. There is no deadline to use the money and no annual forfeiture.

This is the structural difference between an HSA and a Flexible Spending Account. FSAs generally operate on a “use it or lose it” basis, where unspent dollars revert to the employer after a grace period. HSAs work the opposite way. The account belongs to you regardless of whether you change jobs, switch to a non-high-deductible health plan, or retire. If you leave a high-deductible plan, you lose the ability to make new contributions, but every dollar already in the account stays put and can still be withdrawn tax-free for qualified medical expenses.²

So an unused balance is not a problem to solve. It’s the account working the way it was designed to work.

You Can Invest the Balance You Don’t Spend

Once your balance grows beyond what you need for near-term medical costs, most HSA providers let you invest the surplus in mutual funds, index funds, or other options similar to what you’d find in a 401(k). Providers typically require you to keep a cash threshold of around $1,000 to $2,000 in the base account before unlocking investment access, with only amounts above that threshold eligible to be invested.

The tax treatment is where HSAs outperform almost every other savings vehicle. Contributions go in tax-free (pretax if through payroll, or deductible if contributed directly). Investment gains, dividends, and interest grow without federal income tax as long as the money stays in the account.² Withdrawals for qualified medical expenses come out tax-free too. That’s a triple tax advantage no IRA or 401(k) can match.

Fees are worth watching. HSA accounts can carry maintenance fees, investment fees, and underlying fund expense ratios. Combined costs vary widely by provider. Some charge no maintenance fees at all; others charge a few dollars per month on cash accounts plus additional fees on invested balances. If your provider’s fees are eating into returns, you can move the account to a lower-cost provider through a trustee-to-trustee transfer at any time.²

You Can Reimburse Yourself Years Later

Here is where unused HSA money gets genuinely powerful. There is no time limit to reimburse yourself for a qualified medical expense. You can pay for a doctor visit out of pocket today, keep the receipt, let your HSA balance grow for 10 or 20 years, and then pull the reimbursement tax-free whenever you want.² The only requirement is that the expense was incurred after you established the HSA.

This creates a legitimate strategy. Pay medical bills from your checking account, save the receipts, and let the HSA compound tax-free for years. When you eventually need the money, reimburse yourself for those old expenses and the withdrawal is completely tax-free. Some people accumulate decades of unreimbursed medical receipts as a kind of tax-free withdrawal bank they can tap in retirement.

The catch is record-keeping. The IRS requires you to keep documentation showing that each distribution went toward a qualified medical expense that wasn’t already reimbursed from another source or claimed as an itemized deduction.² The general statute of limitations for IRS audits is three years, but if you’re planning to reimburse yourself for expenses from years ago, keep those receipts for as long as the money stays in the account. Digital copies stored in cloud backup work fine.

What Changes at Age 65

Before 65, withdrawing HSA money for anything other than qualified medical expenses triggers a steep penalty: 20% of the distribution on top of regular income tax.¹ That penalty exists specifically to discourage people from treating the account as a general savings vehicle before retirement.

Once you reach 65, the 20% penalty disappears permanently.¹ At that point, your HSA essentially functions like a traditional IRA for non-medical spending. You can withdraw funds for rent, travel, groceries, or anything else. The distribution counts as ordinary income and gets taxed at whatever bracket you fall into that year, but there is no additional penalty. For medical expenses, withdrawals remain completely tax-free.

This dual nature is what makes leaving money in the account so low-risk. If your health stays better than expected and you don’t need the money for medical care, it converts into general retirement income. If medical costs spike, you have a dedicated tax-free pool to draw from.

Paying Medicare Premiums From Your HSA

After 65, one of the most useful ways to deploy leftover HSA funds is paying Medicare premiums tax-free. Withdrawals can cover premiums for Medicare Part A, Part B, Part D, and Medicare Advantage plans without owing any tax on the distribution.² Medigap (Medicare supplement) premiums are the exception and cannot be paid tax-free from an HSA.

Even if your Medicare premiums are automatically deducted from your Social Security check, you can still reimburse yourself from the HSA after the fact.

Other Insurance Premiums That Qualify

Outside of Medicare, HSA money generally cannot be used to pay insurance premiums tax-free. Federal law carves out three other exceptions:² COBRA continuation coverage after leaving a job, health insurance premiums while you’re collecting federal or state unemployment, and premiums for qualified long-term care insurance. Any other insurance premium paid from the HSA triggers income tax, plus the 20% penalty if you’re under 65.

What Happens to Unused HSA Money When You Die

Where leftover HSA money goes depends entirely on your beneficiary designation.

Spouse as Beneficiary

If your spouse is the named beneficiary, the account simply becomes their HSA. They take over as if they had always owned it, with full access to use the funds tax-free for their own medical expenses or to continue investing the balance.¹ No tax is owed on the transfer, and the account keeps all its HSA characteristics.

Non-Spouse Beneficiary

If anyone other than a spouse inherits the account, the HSA ceases to exist as of the date of death. The entire fair market value of the account becomes taxable income to the beneficiary in the year the original owner dies.² That can be a significant tax hit for a beneficiary already in a high bracket. The taxable amount can be reduced by any qualified medical expenses of the deceased that the beneficiary pays within one year of the death.¹

Estate as Beneficiary

If the estate is the beneficiary, either by designation or because no beneficiary was named, the account’s value gets included on the deceased owner’s final income tax return.² The practical takeaway: always name a beneficiary. If your spouse is alive, naming them preserves the full tax advantage. If you don’t have a spouse, naming a specific individual at least avoids running the balance through the estate.

1
Office of the Law Revision Counsel. 26 USC 223 – Health Savings Accounts
2
Internal Revenue Service. Publication 969 (2025), Health Savings Accounts and Other Tax-Favored Health Plans