Most people treat their HSA like a checking account for medical bills. That’s the wrong move, and it costs them one of the best tax advantages available to any investor.
A Health Savings Account gives you something no other account in the tax code offers: a triple tax advantage. You contribute pre-tax dollars, those dollars grow tax-free, and you withdraw them tax-free when you spend them on qualifying medical expenses. A traditional IRA gives you two of those three. A Roth IRA gives you two of those three. The HSA gives you all three, and after age 65, it functions like a traditional IRA for non-medical expenses too.
The problem is that most HSA holders leave this advantage on the table. They use their HSA as a pass-through account, spending down their balance every year on prescriptions and co-pays instead of letting it compound. This article explains exactly how to use your HSA the right way, from contribution limits to investment strategies to the retirement income play most people have never heard of.
What Is an HSA and Who Can Open One?
An HSA is a tax-advantaged savings account designed to pair with a High-Deductible Health Plan (HDHP). To contribute to an HSA in 2025, your health insurance must meet IRS criteria: a minimum deductible of $1,650 for self-only coverage or $3,300 for family coverage, with out-of-pocket maximums capped at $8,300 for self-only and $16,600 for family.
If your employer offers an HDHP, you can open an HSA through your plan administrator. If you’re self-employed or your employer’s HDHP doesn’t include HSA access, you can open one independently at a bank or brokerage that offers them. You cannot contribute to an HSA if you’re enrolled in Medicare, claimed as a dependent on someone else’s taxes, or covered by a non-HDHP health plan (including a spouse’s FSA in some situations).
One important distinction: an HSA is not the same as a Flexible Spending Account (FSA). FSAs are use-it-or-lose-it accounts with a “carryover” limit of $660 in 2025. Your HSA balance rolls over every year with no limit. That rollover feature is what makes it powerful as a long-term investment vehicle.
The Triple Tax Advantage, Explained
Here’s how the three tax benefits actually work in practice.
Pre-tax contributions. When you contribute to an HSA through payroll deduction, the money comes out before federal income tax, state income tax (in most states), and FICA taxes. That last one matters: most retirement accounts skip FICA savings, but the HSA doesn’t. For someone in the 22% federal bracket plus a 5% state tax rate, a $1,000 HSA contribution effectively costs around $730 out of pocket after tax savings.
Tax-free growth. Once money is in your HSA, it grows without being taxed. If you invest it in index funds and your balance grows from $10,000 to $40,000 over 15 years, you owe zero tax on that $30,000 in gains. Compare that to a standard brokerage account, where you’d owe capital gains taxes on each sale or distribution.
Tax-free withdrawals for medical expenses. When you withdraw HSA funds to pay for qualifying medical expenses, you pay no federal income tax on the withdrawal, regardless of how much the account has grown. Qualifying expenses include deductibles, co-pays, dental, vision, prescriptions, and a long list of other medical costs. The IRS publishes a full list in Publication 502.
Put all three together: you never pay income tax going in, you never pay tax on gains, and you never pay tax coming out, as long as the money is used for medical expenses.
2024 and 2025 Contribution Limits
For 2024, the IRS set HSA contribution limits at $4,150 for self-only coverage and $8,300 for family coverage. If you were 55 or older at any point during 2024, you could contribute an additional $1,000 catch-up contribution.
For 2025, those limits increased to $4,300 for self-only and $8,550 for family coverage. The $1,000 catch-up for those 55 and older remains the same.
These limits include both employee and employer contributions. If your employer contributes $1,000 to your HSA, your personal contribution limit for 2025 is $3,300 (self-only) or $7,550 (family), not the full limit.
You have until your tax filing deadline to make prior-year HSA contributions. That means you can make a 2025 HSA contribution as late as April 15, 2026.
Why Most People Are Using Their HSA Wrong
A 2023 report from the Plan Sponsor Council of America found that only about 9% of HSA account holders invest any portion of their balance. The rest keep everything in cash. Given that the average HSA balance sits around $4,300, according to Devenir’s 2023 HSA Research Report, the gap between what people are doing and what they could be doing is significant.
Here’s the mistake: if you use your HSA as a checking account for medical expenses, you get one tax break. You avoid income tax on the way in. But if you invest your HSA and let it grow, you capture all three tax benefits, and the math compounds dramatically over time.
Consider two people, each with a self-only HDHP. Both contribute $4,300 in 2025. Person A spends their balance every year on medical expenses. Person B pays out of pocket for medical expenses, invests the full $4,300, earns an average 7% annual return, and does this for 20 years. Person A ends each year with a $0 HSA balance. Person B ends 20 years with approximately $177,000 in their HSA, completely untouched by taxes on the growth.
The most common objection is: “But I can’t afford to pay my medical bills out of pocket.” That’s a legitimate constraint for many people. But if you can cover routine medical expenses from your regular cash flow, even partially, the HSA investing strategy is worth it.
How to Actually Invest Your HSA
Most HSA accounts have a cash holding threshold, typically $1,000 to $2,000, before they allow you to invest. Once you cross that threshold, you can usually invest in a menu of mutual funds or ETFs similar to what you’d find in a 401(k). Some HSA providers, including Fidelity and Lively, offer brokerage-style access with broader investment options and no minimum balance requirement before investing.
Your provider matters. Fees vary significantly across HSA providers. Some charge monthly maintenance fees of $3 to $5, plus fund expense ratios. Others, like Fidelity’s HSA, charge no monthly fees and offer low-cost index funds. If your employer offers an HSA through a high-fee provider, you can often keep contributing there to capture the payroll tax savings, then do a once-per-year transfer to a lower-cost provider where you actually invest the money.
A simple investment strategy: choose a low-cost total market index fund or a target-date fund matched to your expected retirement year. This is not the account to experiment with sector bets or individual stocks. Treat it like a Roth IRA and prioritize long-term, diversified growth.
The “Receipt Box” Strategy: Reimbursing Yourself Years Later
Here’s the part most HSA guides skip. The IRS does not require you to reimburse yourself for medical expenses in the same year you incur them. There is no statute of limitations on HSA reimbursements.
That means you can pay your medical bills out of pocket today, save every receipt, let your HSA balance compound tax-free for 10 or 20 years, and then reimburse yourself from the HSA later. The reimbursement is still tax-free, even if you’re withdrawing money that has grown substantially since you incurred the original expense.
A concrete example: you have a $2,000 medical expense in 2025 that you pay out of pocket. You save the receipt. Your HSA grows over 15 years. In 2040, you withdraw $2,000 from your HSA as reimbursement for that 2025 expense. That withdrawal is completely tax-free.
The IRS requires that the expense was incurred after your HSA was established and that it was a qualifying medical expense at the time. Keep your documentation: explanation of benefits (EOB) statements from your insurer, itemized receipts, and a simple spreadsheet tracking the date, amount, and nature of each expense. Store this digitally; paper receipts fade.
Some financial planners call this an “HSA receipt box” strategy because the physical or digital record-keeping is the key to making it work legally. The longer you hold off on reimbursement, the more compounding you capture before pulling the money out.
What Happens to Your HSA After Age 65
Once you turn 65 and enroll in Medicare, you can no longer contribute to an HSA. But you can still use the money you’ve accumulated, and the rules change in your favor.
Before 65, withdrawals for non-medical expenses are subject to income tax plus a 20% penalty. That’s a steep price for accidentally using the wrong account. After 65, the 20% penalty disappears. Non-medical withdrawals are simply taxed as ordinary income, exactly like a traditional IRA distribution. This is why the HSA is sometimes called “the IRA with a bonus” for people in good health: if you never need the money for medical expenses, it still functions as a retirement account.
In practice, most retirees end up with plenty of qualifying medical expenses: Medicare premiums (Part B, Part D, and Medicare Advantage), long-term care insurance premiums, dental and vision care, and out-of-pocket healthcare costs. All of these qualify for tax-free HSA withdrawals. Fidelity estimates that the average retired couple will need approximately $330,000 to cover healthcare costs in retirement. An invested HSA can be a dedicated fund specifically for that purpose.
There is one planning note worth flagging: if you’re approaching 65 and thinking about delaying Medicare enrollment while still covered by an employer HDHP, you can keep contributing to your HSA. But the moment you sign up for Medicare, contributions must stop, and you should stop contributing in the six months before your Medicare start date if you claim Social Security at 65, because Medicare Part A retroactively covers those six months and a retroactive HSA contribution creates a penalty.
Common HSA Mistakes to Avoid
Leaving money in cash. The most expensive mistake. Cash in an HSA earns minimal interest and captures only one of the three tax benefits. If your balance exceeds your emergency medical buffer (your HDHP deductible is a reasonable benchmark), the rest should be invested.
Choosing the wrong provider. Your employer’s default HSA provider may be convenient, but high fees compound against you the same way low fees compound for you. Compare your provider’s monthly fees and investment options. Switching is possible and often worth it.
Not keeping receipts. If you plan to use the delayed reimbursement strategy, documentation is non-negotiable. Create a dedicated folder, physical or digital, and file every explanation of benefits and medical receipt as you go.
Confusing HSAs with FSAs. FSAs have a use-it-or-lose-it structure (with a small carryover). HSAs don’t. If you’ve been managing your HSA like an FSA, stop. You’re leaving years of compound growth on the table.
Contributing when ineligible. If you enroll in Medicare, get covered under a non-HDHP plan, or get claimed as a dependent, you’re no longer eligible to contribute. Excess contributions are taxed and subject to a 6% excise penalty. Check your eligibility every year.
The Bottom Line
The HSA is the only account in the U.S. tax code that offers pre-tax contributions, tax-free growth, and tax-free withdrawals simultaneously. For people with access to a high-deductible health plan, it deserves a spot at the top of the investment priority list, alongside a 401(k) match and a Roth IRA.
Three things to do if you have an HSA right now: check whether your balance exceeds your deductible (and if it does, invest the excess); compare your current provider’s fees to lower-cost alternatives like Fidelity; and start keeping receipts for out-of-pocket medical expenses so you can use the delayed reimbursement strategy.
If you don’t have an HSA yet but are on an HDHP, open one this week. The IRS allows you to contribute for the full 2025 tax year as long as you’re enrolled in an HDHP by December 1, 2025. Every year you wait is compounding you’re not capturing.
