A health savings account lets you pay for medical expenses with money that was never taxed, and if you use it strategically, it can double as a long-term investment vehicle. The basics are simple: contribute pre-tax dollars, spend on qualified medical expenses tax-free, and keep whatever you don’t spend. But the real power of an HSA comes from understanding the full range of what counts as a qualified expense, how the reimbursement rules actually work, and when it makes sense to invest the balance instead of spending it down each year.
What You Can Actually Spend It On
The IRS defines qualified medical expenses broadly: anything that diagnoses, cures, treats, or prevents disease, or affects any structure or function of the body. The obvious categories are doctor visits, prescriptions, dental work, and vision care. But the list goes well beyond that.
Dental expenses include cleanings, X-rays, fillings, braces, and dentures. Eye care covers exams, glasses, contact lenses, and laser eye surgery. You can use your HSA for acupuncture, hearing aids (plus batteries and repairs), psychiatric care, fertility treatments including in vitro fertilization, and stop-smoking programs. If a doctor diagnoses you with obesity, hypertension, or heart disease, weight-loss program fees qualify too.
Over-the-counter items are where many people leave money on the table. Bandages, breast pumps and lactation supplies, condoms, pregnancy test kits, sunscreen, and first-aid supplies all qualify. Masks and hand sanitizer purchased to prevent the spread of COVID-19 also count.
Some of the more surprising eligible expenses: the cost of buying, training, feeding, grooming, and providing veterinary care for a guide dog or other service animal. Lodging while traveling for medical care qualifies up to $50 per night per person, as long as the trip is primarily for treatment at a licensed facility. Even lead-based paint removal in your home can qualify if it’s to protect a child who has or had lead poisoning.
What doesn’t qualify? Cosmetic procedures that aren’t medically necessary, gym memberships (unless prescribed for a specific condition), and general health items like vitamins or supplements taken for overall wellness rather than a diagnosed condition.
Paying for Expenses Two Ways
You have two options when a medical expense comes up. The first is straightforward: use your HSA debit card or pay directly from the account at the point of sale. Many HSA providers issue a Visa or Mastercard tied to your account, and most pharmacies and medical offices accept them.
The second option is to pay out of pocket now and reimburse yourself later. This is where HSAs get interesting. The IRS sets no deadline for reimbursement. You can pay for a $200 eye exam today with your personal credit card, save the receipt, and withdraw $200 from your HSA five, ten, or even twenty years from now, completely tax-free. The only requirement is that the expense was incurred after you established the HSA.
This matters because any money sitting in your HSA can be invested and grow tax-free in the meantime. Paying out of pocket when you can afford to, then letting your HSA balance compound, is one of the most effective long-term strategies available.
Record Keeping That Protects You
The IRS requires you to keep records proving three things: that each distribution paid for a qualified medical expense, that the expense wasn’t reimbursed from another source (like insurance), and that you didn’t also claim the expense as an itemized deduction on your tax return. You don’t send these records with your return, but you need to have them if the IRS ever asks.
In practice, this means saving every receipt, explanation of benefits statement, and proof of payment. A simple system works well: photograph or scan each receipt when you get it, and store the files in a dedicated folder organized by year. If you plan to reimburse yourself years later, good records are essential. An app or spreadsheet tracking the date, amount, and description of each expense makes this painless. The longer the gap between paying and reimbursing, the more important those records become.
Investing Your HSA Balance
Most HSA providers let you invest your balance in mutual funds, index funds, or other options once you hit a minimum cash threshold. That threshold varies by provider but typically falls between $1 and $1,000. Any amount above the threshold can be moved into investments.
The tax treatment is what makes HSA investing so powerful. Contributions go in tax-free. Investment gains grow tax-free. And withdrawals for qualified medical expenses come out tax-free. No other account in the tax code offers this triple tax advantage.
A practical approach: keep enough cash in your HSA to cover your annual deductible or a few months of expected medical costs, and invest the rest. If your employer offers a choice of HSA providers, compare the investment options and fees the same way you would a 401(k). Low-cost index funds are typically the best choice for long-term growth. If your employer’s default provider has limited options or high fees, many people transfer their balance to a different HSA provider with better investment choices once or twice a year.
How Your HSA Changes After 65
Before age 65, withdrawing HSA funds for non-medical expenses triggers income tax plus a 20% penalty. After 65, that penalty disappears. You’ll still owe regular income tax on non-medical withdrawals, which makes the account function like a traditional IRA for non-medical spending. For medical expenses, withdrawals remain completely tax-free at any age.
This is why many financial planners treat the HSA as a retirement account. If you can afford to pay medical bills out of pocket during your working years, your HSA balance has decades to grow. In retirement, you can withdraw tax-free for Medicare premiums, prescription drugs, dental work, hearing aids, long-term care, and every other qualified expense. Or, if you need the money for something else entirely, you simply pay income tax on the withdrawal with no penalty.
One important detail: once you enroll in Medicare, you can no longer contribute to an HSA. But you can continue spending or investing the balance you’ve already built, and there’s no requirement to draw it down by a certain age. The money is yours permanently.
Making the Most of Contributions
If your employer offers payroll contributions to your HSA, use them. Money contributed through payroll deductions avoids both income tax and FICA taxes (Social Security and Medicare taxes), which saves you an additional 7.65% compared to contributing on your own after the fact. If you contribute outside of payroll, you’ll still get the income tax deduction when you file, but you won’t recapture those payroll taxes.
Try to contribute the annual maximum if your budget allows. Even in years when your medical expenses are low, the money rolls over indefinitely. There’s no “use it or lose it” rule like with a flexible spending account. Every dollar you contribute but don’t spend this year becomes part of a growing balance that works for you in future years or in retirement.
If you’re 55 or older, you can make an additional catch-up contribution of $1,000 per year on top of the standard limit. If both spouses are 55 or older and each has their own HSA, each can make the catch-up contribution separately.
Expenses Before Your HSA Existed
One rule catches people off guard: you cannot use your HSA to reimburse expenses incurred before the account was established. If you had surgery in March but didn’t open your HSA until April, that surgery doesn’t qualify for tax-free reimbursement. The clock starts on the date your HSA is officially set up, not the date your high-deductible health plan began. If you’re planning to open an HSA, do it as early in the year as possible so every expense from that point forward is eligible.