Should I Use My HSA as a “Stealth IRA”?

Your HSA is the most tax-advantaged account you own: money goes in untaxed, grows untaxed, and comes out untaxed for medical costs. If you can pay your medical bills another way and leave the HSA alone, it quietly becomes an extra retirement account — a "stealth IRA." This recipe shows how to test whether that move helps your plan, and what it costs.

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Why it can be such a powerful move

It’s one of the highest-leverage tax moves available to a household with the cash flow to cover medical bills out of pocket:

• The IRS lets you reimburse yourself in any future year. A qualified medical expense you pay today can be withdrawn from the HSA tax-free decades later — there’s no deadline. So as long as you keep your receipts, deferring HSA withdrawals isn’t a sacrifice: the money is still yours to pull out tax-free whenever you want, and it compounds tax-free in the meantime.
• Tax-free growth and tax-free medical withdrawals — for life. The real win is while you’re alive: the deferred balance keeps compounding untaxed and later covers medical costs (including Medicare premiums) without adding a dollar to your taxable income. That’s income you’d otherwise have generated by drawing a taxed Traditional account.

What it won’t do: hand the kids money tax-free. The HSA’s tax-free magic is really for you (and a surviving spouse), while you’re alive. Leave an HSA to a non-spouse heir — your kids — and the whole balance is taxable to them as ordinary income in the year of death (plus state tax). That’s actually harsher than an inherited IRA, which the heir can draw down over 10 years to spread the tax; an HSA gives no such window, and no step-up. So a big leftover HSA isn’t a tax-free gift to the next generation. (A spouse is different: they inherit it tax-free — set the account’s Beneficiary to Spouse and the model reflects that.) Use this strategy for the tax you save during your own lifetime, not for what it leaves the kids. See Limitations.

The quick version

1. Turn on HSA "stealth IRA" on the Strategy tab.
2. Save it as a named strategy — "HSA stealth."
3. Run Comparison and check the HSA ending balance and after-tax legacy against your baseline.

Step by step

1. Turn on the stealth strategy. On the Strategy tab, enable HSA "stealth IRA" and set the reimbursement age — the age you want to leave the HSA untouched until. Until then, medical costs are paid from VEBA (and your other accounts) first, so the HSA is left to compound.

When does the HSA get spent down — and can you change it? It compounds untouched until the reimbursement age, then rejoins the medical cascade (drawn right after VEBA) and starts covering medical costs. The default is 65 — after 65 an HSA withdrawal for any purpose owes only ordinary income tax, with no 20% penalty. You control the timing: an earlier age taps it sooner, a later one defers longer, and setting it past your plan’s horizon leaves the HSA essentially untouched so it passes to your heirs as legacy. (The age keys off Person 1’s age — the plan’s reference person — not a per-account or per-spouse setting.)

2. Save it as a named strategy (the Strategies button) — "HSA stealth."

3. Run Comparison on the Compare tab; with Compare against baseline on (the default), your baseline runs head-to-head with the stealth version on the same market sequences. Load Baseline (⤺) returns you to your plan.

What to look at

• HSA ending balance — this is the lever. It should be meaningfully higher with stealth on.
• After-tax legacy (P50) — the net effect on what you leave behind. It may still rise (you preserved a balance and spent from elsewhere), but remember a leftover HSA is taxed at death (ordinary income to a non-spouse heir), so the legacy gain is net of heir tax, not the full HSA balance.
• The during-life tax savings — often the bigger story than legacy: by covering medical from a tax-free HSA later, you avoid taxable Traditional withdrawals in those years. Check the tax summary across the two runs.
• The cost, in the other accounts — stealth doesn’t create money; it shifts which accounts you draw down. Expect lower ending balances in your Traditional/Roth/taxable accounts during the deferral years, and extra Traditional withdrawals can nudge your taxable income (and even IRMAA) up in the meantime.
• Success Rate — confirm that paying medical from other accounts first doesn’t strain the plan. If it does, you may not have the spare cash flow this strategy assumes.

Who this is (and isn’t) for

• You need another way to pay medical bills during the deferral years — out of pocket, VEBA, or general savings. If your HSA is your only realistic medical funding source, stealth has little room to work.
• You have to keep your receipts. The whole strategy rests on being able to substantiate a later tax-free reimbursement.
• Value it for the during-life tax savings, not a bequest to the kids. For a non-spouse heir, a leftover HSA is taxed as ordinary income on the full balance in the year of death — no step-up, and none of the 10-year spreading an inherited IRA allows, so it’s if anything harsher than inheriting a Traditional account (see Limitations). Don’t run this purely to grow an inheritance for the next generation. A spouse inherits it tax-free — set the account’s Beneficiary to Spouse and the model reflects that.
• Check with a professional before you commit. The rules for reimbursing yourself years later — and the recordkeeping they require — are strict. Run it by your accountant or financial planner first to make sure you’re set up to meet every tax and receipt requirement before you lean on this strategy.