The HSA: The Best Retirement Account Nobody Uses Right

An HSA is the only account the IRS lets you fund pre-tax, grow tax-free, and withdraw tax-free for medical costs. For 2026 you can put in $4,400 solo or $8,750 for a family, plus $1,000 more if you're 55 or older. Most people never invest a dollar of it.

Open enrollment season has a rhythm to it. HR sends the benefits packet, you skim it for ten minutes between meetings, and you re-elect whatever you had last year because reading twelve pages about deductibles sounds like a special kind of punishment. Somewhere in that packet sits a line for a Health Savings Account, and most people either skip it or treat it as a debit card for copays and contact lenses.

That's a mistake. An HSA works like a retirement account wearing a health-perk costume, and it's a better one than almost anything else sitting in your benefits packet.

Money goes into the account before tax. It grows with no tax. It comes out with no tax when it pays for qualified medical costs (IRS Publication 969). No other account does all three.

A 401(k) taxes you on the way out. A Roth IRA taxes you on the way in.

For 2026 the limits are $4,400 for self-only coverage and $8,750 for a family (IRS Rev. Proc. 2025-19). From age 55 the law adds a $1,000 catch-up (IRC §223). The balance rolls over every year, and the account follows you through job changes and into retirement.

According to long-term research from the Employee Benefit Research Institute, only about 13% of HSA holders ever invest any portion of their balance. The other 87% leave it sitting in cash, usually earning close to nothing, and treat it exactly like a checking account for medical bills.

That's a reasonable habit for someone with a $600 balance and a kid who needs stitches every summer. It's an expensive habit for someone who could be maxing out the account, paying small medical bills out of pocket, and letting the rest compound for decades. Most HSA providers let you invest the balance above a small cash cushion, usually $1,000 to $2,000, into the same kind of mutual funds and index funds you'd find in a 401(k).

There's no deadline on reimbursing yourself from an HSA. If you pay a $400 dental bill out of pocket today and let your HSA keep growing, you can reimburse yourself for that $400 fifteen years from now, tax-free, as long as you have the receipt. In the meantime, that $400 has been invested and compounding the whole time.

That means the smartest way to run an HSA, once you can afford it, is to pay current medical costs with regular cash, keep every receipt in a folder, and let the account invest untouched. Decades later, you either reimburse yourself for a stack of old receipts or simply let it ride into retirement, when the money can be spent on anything at all, not just medical costs, once you turn 65.

A Roth IRA still wins on flexibility since there's no health-expense requirement at any age, though dollar for dollar nothing beats the HSA's tax treatment while you're still working, and few employees are anywhere near maxing out both. If your income is too high to contribute to a Roth IRA directly, a backdoor Roth IRA is worth understanding too, since it gives you another tax-free retirement bucket alongside your HSA.

If you have no emergency fund yet and a medical bill would otherwise go on a credit card, then it makes sense to spend it. Most people are in this bucket for the first few years of having an HSA, and that's fine. The real mistake is staying in that phase long after you can afford to move past it.

Invest it and let it grow if you've built a cash cushion above your provider's investment threshold, and you're already contributing to your 401(k) up to any employer match.

Once those three are true, every dollar you leave uninvested in an HSA is a dollar losing ground to inflation while wearing the best tax status in the entire tax code.

Open enrollment is the window most people have to change how their HSA works, so it's worth doing this before the packet goes back in the drawer.

Check if you're eligible. You need to be enrolled in a qualifying high-deductible health plan to contribute. Not every HDHP-labeled plan qualifies, so check the deductible minimums in your plan documents against IRS Publication 969 before assuming you're covered.

Push your contribution as close to the max as your budget allows. Even an extra $100 a month adds up differently in an account that's never taxed than it does anywhere else you could put it.

Ask your provider if investing is available and what the threshold is. Some employer-sponsored HSAs default to a low-interest cash account and require you to actively opt into investment options. That step is easy to miss.

Start a receipts folder today, even if you're not investing yet. It costs nothing to save a PDF, and it gives you the option to reimburse yourself tax-free decades from now instead of today.

Your HSA is one piece of a much bigger benefits package, and most of that package has the same problem, people sign up for whatever was pre-selected last year and never look again. It's worth taking a closer look at how to get more out of your full benefits package while you're already reviewing the open enrollment paperwork.

Open enrollment only comes around once a year, and the HSA line is easy to skip past on the way to the parts that feel more urgent. It's worth slowing down for, since it's the one account on that packet quietly outperforming almost everything else in it.