Most people (understandably) use an HSA like a medical checking account. Money goes in, the debit card gets swiped, the balance zeros out by year-end. That works, but sort of misses the point.
An HSA is the most tax-advantaged account in the US tax code. No other account gives you three tax breaks on the same dollar. Money goes in pre-tax, grows tax-free, and comes out tax-free for qualified medical expenses.
The catch is that the full advantage only shows up for people who can afford to leave it alone.
If you’re draining the account every year to cover copays and crown replacements and ER visits, you’re getting one tax break, the one on the way in. That’s still good, but it’s a fraction of what the account can do. The real power is investing the balance and letting it compound untouched, the same way you’d run a 401(k), except on the exit—your 401(k) gets taxed on the way out, and your HSA doesn’t.
For the clients we work with—high-income families, usually in their 30s and 40s, usually with young kids—this is the tension. You’re in the years with the highest medical bills of your life so far (deliveries, pediatricians, the ear infections, the orthodontia) and also in the years with the longest compounding runway you’ll ever have. The temptation is to use the HSA for current bills.
The 2026 numbers
To fund an HSA you need to be enrolled in a high-deductible health plan (HDHP). For 2026, that means a deductible of at least $1,700 for individual coverage or $3,400 for family coverage, with annual out-of-pocket maxes of $8,500 and $17,000 respectively.
Contribution limits for 2026 are $4,400 for individuals and $8,750 for families, and anyone 55 or older can add another $1,000 catch-up. Employer contributions count against the same limit, but they’re free money, so take them.
What “used correctly” actually looks like
Three things have to be true for the HSA to function as a retirement account.
First, you max the contribution every year. Second, you invest the balance—most HSA custodians let you put anything above a small cash threshold into the market, and most account holders never do, which makes this the single biggest lever in the strategy and the one that usually sits untouched. Third, you pay current medical bills out of pocket, from regular cash flow, rather than from the HSA.
The third one is where this gets hard. It requires covering medical expenses twice, once to the doctor and once into the HSA, which isn’t realistic for a lot of families. For our clients, it usually is, as long as you plan for it.
The math
$8,750 per year for 25 years, invested at a 7 percent real return, grows to roughly $554,000. All of it is tax-free going in, tax-free growing, and tax-free coming out as long as you use it for medical expenses, which you will—retiree households spend money on healthcare, often into the six figures per person over the course of a retirement, and that’s before long-term care.
Once you hit 65, the 20 percent penalty on non-medical withdrawals goes away, and the account starts functioning like a traditional IRA for everything else. Worst case, your HSA becomes an IRA. Best case, it stays a Roth.
A quick note on receipts
If you do pay a medical bill out of pocket, keep the receipt. The IRS has never put a statute of limitations on HSA reimbursement, which means you can pay $500 for a dental crown today, file the receipt, let the equivalent balance compound inside the HSA for 20 years, and reimburse yourself tax-free whenever you want. People call this receipt stacking, and it’s a way to preserve optionality without sacrificing the growth.
Where to watch your step
Once you enroll in Medicare, you can’t contribute to an HSA anymore, so this is worth coordinating with any plans to delay Medicare past 65.
If you’re covered under someone else’s HDHP, or if you or your spouse have a general-purpose FSA, you may not be eligible to contribute at all. The rules around family coverage and dependent status get specific quickly, and they’re worth a careful read before you assume you’re in the clear.
Before 65, withdrawals for non-medical reasons are taxed as income and hit with a 20 percent penalty, which is a steep price for breaking discipline.
Qualifying expenses are a bigger list than most people realize: glasses, contacts, therapy, most dental, menstrual products, chiropractors, SPF sunscreen. When in doubt, check IRS Publication 502 or ask us.
If you can afford not to spend it…
The HSA is one of the best accounts out there.
For some of our clients, running the HSA as a stealth retirement account can be a savvy move.
Nothing in this essay is investment, legal, or tax advice. It’s a general discussion of concepts I find useful in my work and shouldn’t be relied on as a recommendation for your specific situation. Talk to a qualified advisor (ideally one who knows you) before acting on anything here.
