HSA "Stealth IRA" Triple-Tax-Advantage Calculator
Project an invested HSA balance and compare it with the same pre-tax dollars in a taxable brokerage account.
HSA Strategy Inputs
Federal + state income tax, plus 7.65% FICA only if you contribute through payroll.
Upfront Tax Saved / Yr
$2,800 / yr
Contribution × tax rate
Projected HSA Balance
$688,343
25-Year Compound Growth
Extra Wealth vs Brokerage
+$322,644
Same pre-tax dollars, taxable account
The three tax benefits of an HSA
Contributions are deductible, and those made through an employer's cafeteria plan also avoid Social Security and Medicare tax.
Dividends and capital gains can compound without annual tax drag or 1099-DIV taxes.
Withdrawals for qualified medical expenses are tax-free at any age; after 65, other withdrawals are taxed as income without the 20% additional tax.
HSA vs. Taxable Brokerage Compounded Wealth
HSA growth untaxed; taxable account return reduced by 20% for tax on dividends and gains.
The "Shoebox Receipt" Strategy Explained
IRS Publication 969 allows tax-free reimbursement of qualified medical expenses incurred after the HSA was established and does not require withdrawals each year. If you pay a $1,000 bill out of pocket and keep the receipt, the $1,000 can stay invested; at 8.5% a year it would be about $5,112 after 20 years, and the original $1,000 could then be withdrawn tax-free against that receipt.
What this calculator does
This calculator projects a Health Savings Account used as a long-term investment account, an approach often called the "Stealth IRA": you contribute each year, invest the balance, pay current medical bills from other money, and keep the receipts to reimburse yourself later. You choose self-only or family coverage, the annual contribution, whether you qualify for the age-55 catch-up, a combined tax rate, an expected return and the number of years. The calculator reports the tax saved on each year's contribution, the projected HSA balance, and how much more that is than the same pre-tax dollars invested in a taxable brokerage account.
Contributions above the 2026 limit for the coverage you select are capped automatically, and the note under the results says when that has happened. The page on the HSA triple-tax calculator focuses on the payroll-tax side of contributing; this one focuses on what the invested balance can do over time and what happens to it later in life.
How the math works
The 2026 limits are $4,400 for self-only coverage and $8,750 for family coverage under IRS Revenue Procedure 2025-19, plus $1,000 a year from age 55 under IRS Publication 969. The limit covers your contributions and your employer's combined.
The HSA balance uses the future value of a level annual contribution made at the end of each year, FV = Pmt × ((1 + r)n − 1) / r, with no tax on the growth. The comparison account receives the contribution after tax at your combined rate, and its return is reduced by 20% each year (8.5% becomes 6.8%) to stand in for tax on dividends and realized gains. No tax is charged when the taxable account is eventually sold, and the HSA is assumed to be spent on qualified medical expenses. The tax saving is the contribution times your combined rate. That rate should include the 7.65% payroll tax only if you contribute through an employer's cafeteria plan, which IRS Publication 15-B treats as exempt from Social Security and Medicare tax.
Worked example
The default inputs: family coverage at the 2026 maximum of $8,750 a year, a 32% combined tax rate, an 8.5% expected return and 25 years.
- Tax saved each year: $8,750 × 32% = $2,800.
- HSA balance: $8,750 a year at 8.5% for 25 years reaches $688,343, of which $469,593 is growth.
- Taxable account: $8,750 less 32% tax leaves $5,950 a year, growing at 6.8%, which reaches $365,699.
- Difference: $322,644 in the HSA's favor, provided the HSA is used for qualified medical expenses.
How the tax rate and return change the result
The HSA balance depends only on the contribution, return and time. The advantage over a taxable account depends on the tax rate too, because a higher rate both shrinks what goes into the taxable account and makes the HSA's deduction worth more. Family coverage at $8,750 a year for 25 years:
| Tax rate | Return | Tax saved per year | HSA balance | Taxable account | Difference |
|---|---|---|---|---|---|
| 22% | 8.5% | $1,925 | $688,343 | $419,479 | $268,864 |
| 32% | 8.5% | $2,800 | $688,343 | $365,699 | $322,644 |
| 40% | 8.5% | $3,500 | $688,343 | $322,676 | $365,667 |
| 32% | 7.0% | $2,800 | $553,429 | $308,634 | $244,795 |
| 32% | 5.0% | $2,800 | $417,612 | $247,793 | $169,819 |
With self-only coverage at $4,400 a year, the same 32% rate and 8.5% return give an HSA balance of $346,138 and a difference of $162,244. Returns in these rows are assumptions; an 8.5% average over 25 years is not assured, and a lower return reduces both accounts.
The receipts strategy in numbers
The strategy rests on two statements in Publication 969: distributions are tax-free when they pay or reimburse qualified medical expenses incurred after the HSA was established, and you do not have to take withdrawals each year. So a bill paid from your checking account today can be reimbursed from the HSA years later, and in the meantime the money that would have paid it stays invested. At an 8.5% annual return, $1,000 left in the account grows as follows.
| Years invested | Value of the $1,000 | Left in the HSA after a $1,000 reimbursement |
|---|---|---|
| 10 | $2,261 | $1,261 |
| 20 | $5,112 | $4,112 |
| 30 | $11,558 | $10,558 |
These figures are simple annual compounding, $1,000 × 1.085n. The strategy needs records: the receipt, the date of the expense, proof it came after the HSA was opened, and proof it was not reimbursed by insurance or claimed as an itemized medical deduction. Publication 969 does not state a time limit for reimbursing an earlier expense, but the records have to survive for as long as you wait. It also requires cash to pay medical bills from other sources in the meantime.
What happens to the balance at 65 and at death
| Situation | Treatment under Publication 969 |
|---|---|
| Qualified medical expenses, any age | Tax-free |
| Other withdrawals before 65 | Income tax plus a 20% additional tax |
| Other withdrawals at 65 or older | Income tax only |
| Medicare premiums at 65 or older | Qualified expense, except Medigap and other Medicare supplement premiums |
| Contributions after Medicare enrollment | Not allowed; the limit is zero from the first month of enrollment |
| Death, spouse is the designated beneficiary | Becomes the spouse's HSA |
| Death, anyone else is the beneficiary | Stops being an HSA; its value is taxable to the beneficiary that year, less the decedent's medical expenses the beneficiary pays within one year |
This is why the "IRA" in the nickname fits only partly. After 65 an HSA spent on anything other than medical care is taxed like a traditional IRA withdrawal, so the full three-way tax benefit applies only to the medical portion. And unlike a spouse, a child or other heir who inherits an HSA owes income tax on the whole balance in one year, which is worth weighing against spending the balance on medical costs during retirement.
Frequently Asked Questions
What is the "Stealth IRA" strategy?
It means paying current medical expenses out of pocket, investing the HSA balance, and keeping receipts to reimburse yourself later. IRS Publication 969 allows tax-free distributions for qualified medical expenses incurred after the HSA was established and does not require withdrawals each year, so the invested money can grow for years before it is withdrawn against those receipts.
Are there penalties for non-medical withdrawals?
Before age 65, a withdrawal not used for qualified medical expenses is taxed as income and also carries a 20% additional tax. The additional tax does not apply after you reach 65, become disabled or die, so from 65 a non-medical withdrawal is taxed as ordinary income, like a traditional IRA distribution.
Can I contribute to an HSA and an IRA in the same year?
Yes. HSA contributions have their own limit under section 223 of the tax code and are separate from IRA contribution limits, so you can do both if you meet each account's eligibility rules.
Do I need a specific type of health insurance?
Yes. You must be covered by a high-deductible health plan, which for 2026 means a deductible of at least $1,700 for self-only or $3,400 for family coverage, have no disqualifying other coverage, not be enrolled in Medicare, and not be claimable as someone else's dependent.
Can I use my HSA to pay Medicare premiums?
Yes, once you are 65 or older, premiums for Medicare and other health coverage count as qualified medical expenses, except premiums for a Medicare supplemental policy such as Medigap. You can no longer contribute once you are enrolled in Medicare, but you can keep spending the balance.
Sources
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Disclaimer
This calculator is for educational and scenario-analysis purposes only. It does not constitute tax, legal, or investment advice. Consult a licensed CPA or financial advisor for guidance tailored to your specific situation. Limits are from IRS publications current at the review date; returns are inputs, not forecasts.
Built and verified by The Breakeven Math — last reviewed September 18, 2026.