If an item qualifies for your Flexible Spending Account, it almost always qualifies for a Health Savings Account too. Both accounts pull from the same IRS definition of a qualified medical expense, so bandages, prescription copays, glasses, over-the-counter pain relievers, and menstrual products work for either one. The exceptions are narrow but worth knowing: insurance premiums, specific FSA subtypes with restricted scopes, and a few situations where holding one account limits what you can do with the other.
Why the Overlap Is So Close
Both accounts define “qualified medical expense” by pointing to the same federal statute, 26 U.S.C. ยง 213(d), which covers amounts paid to diagnose, treat, or prevent disease and costs that affect any structure or function of the body.1Office of the Law Revision Counsel. 26 USC 213 – Medical, Dental, Etc., Expenses Because the legal foundation is identical, a diagnostic blood test, a pair of prescription eyeglasses, or a bottle of allergy pills that qualifies under one account qualifies under the other.
The CARES Act of 2020 expanded that shared definition. Over-the-counter medications no longer require a prescription to be reimbursable, and menstrual care products like tampons and pads now qualify under both accounts.2Internal Revenue Service. IRS Outlines Changes to Health Care Spending Available Under CARES Act Pain relievers, cold medicine, and similar pharmacy-shelf items are fair game for either account without extra paperwork.
The shared definition also covers durable medical equipment like blood pressure monitors, crutches, and glucose testing supplies, along with professional services such as copays, hospital stays, mental health counseling, and physical therapy. If a retailer labels something FSA-eligible, you can generally assume it is HSA-eligible as well.
Where the Two Accounts Actually Diverge
The exceptions cluster around categories most people don’t think of as “medical expenses.”
The largest gap involves insurance premiums. HSA funds can pay for COBRA continuation coverage, long-term care insurance up to age-based limits, and health coverage while you collect unemployment benefits. If you are 65 or older, your HSA can also cover Medicare Part A, Part B, Part D, and Medicare Advantage premiums, though not Medigap supplemental policies.3Internal Revenue Service. Publication 969 (2025), Health Savings Accounts and Other Tax-Favored Health Plans A standard health FSA cannot reimburse any insurance premiums at all.
There is also a difference after age 65. Non-medical HSA withdrawals made after you turn 65 are taxed as ordinary income but avoid the 20% additional tax that applies to younger account holders.3Internal Revenue Service. Publication 969 (2025), Health Savings Accounts and Other Tax-Favored Health Plans An FSA has no equivalent. You cannot withdraw FSA money for non-medical reasons at any age.
Not Every FSA Follows the Standard Rules
Some accounts labeled “FSA” cover a much narrower slice of expenses than a general-purpose health FSA. Assuming they work the same way is one of the easiest ways to trigger a denied purchase.
Limited-Purpose FSA
A Limited-Purpose FSA exists so you can pair an FSA with an HSA without losing HSA eligibility. The trade-off is a tight scope: these accounts cover only dental and vision expenses such as eyeglasses, contact lenses, orthodontic work, and LASIK surgery. Prescriptions, doctor visits, and hospital bills are off-limits.3Internal Revenue Service. Publication 969 (2025), Health Savings Accounts and Other Tax-Favored Health Plans Before swiping your card at the pharmacy, confirm which type of FSA you actually hold.
Dependent Care FSA
A Dependent Care FSA has nothing to do with medical expenses. It covers caregiving costs for children under 13 or adults who cannot care for themselves and live with you for more than half the year. Eligible spending includes preschool, day camp, and before- or after-school programs. Overnight camps, tutoring, and kindergarten tuition do not qualify.4Internal Revenue Service. Publication 503 (2025), Child and Dependent Care Expenses No medical items are reimbursable from this account.
Post-Deductible FSA
Less common, but worth knowing: a post-deductible FSA covers general medical expenses only after you have met the minimum annual deductible for your health plan. Until that deductible is satisfied, the FSA pays nothing. Like the limited-purpose version, this variant preserves your HSA eligibility.3Internal Revenue Service. Publication 969 (2025), Health Savings Accounts and Other Tax-Favored Health Plans
Having an FSA Can Block Your HSA
Enrolling in a general-purpose health FSA disqualifies you from contributing to an HSA. The IRS treats a general-purpose FSA as “other health coverage” that conflicts with the high-deductible health plan requirement.3Internal Revenue Service. Publication 969 (2025), Health Savings Accounts and Other Tax-Favored Health Plans The rule reaches your spouse’s plan too. If your spouse has a general-purpose FSA that could reimburse your medical expenses, you generally cannot contribute to an HSA.
The workaround is to use an HSA-compatible FSA variant. A limited-purpose FSA, a post-deductible FSA, or a suspended health reimbursement arrangement all leave your HSA contribution ability intact.3Internal Revenue Service. Publication 969 (2025), Health Savings Accounts and Other Tax-Favored Health Plans If you had a general-purpose FSA last year and want to start contributing to an HSA this year, the FSA balance needs to be at zero before the new plan year begins. A leftover balance carried through a grace period will block HSA contributions during those months.
Dual-Purpose Items Need Extra Documentation
Both accounts require you to show that a purchase meets the IRS definition of a medical expense, but the practical burden differs. FSA administrators actively review transactions and will ask for receipts. HSA custodians typically do not police individual purchases, but the IRS can audit HSA distributions years later, so keeping records matters equally.
Keep receipts showing the date, provider or merchant name, a description of the item or service, and the amount paid. A generic credit card slip with only a total is not enough.
Items that could be personal or medical need extra justification. Vitamins, supplements, ergonomic equipment, and specialized footwear are common examples. IRS Publication 502 allows the cost of a personal-use item in a special medical form, but only the excess cost above the standard version qualifies.5Internal Revenue Service. Publication 502 (2025), Medical and Dental Expenses Most plan administrators will ask for a letter from your doctor explaining medical necessity before approving reimbursement. Getting that documentation before you buy saves hassle either way.
Penalties for Buying the Wrong Thing
The consequences for spending on ineligible items differ sharply between the two accounts.
HSA distributions not used for qualified medical expenses are added to your taxable income for the year, and you owe an additional 20% tax on top. The penalty disappears once you turn 65, become disabled, or die.3Internal Revenue Service. Publication 969 (2025), Health Savings Accounts and Other Tax-Favored Health Plans You report these distributions on Form 8889 with your tax return.6Internal Revenue Service. Instructions for Form 8889 (2025) In very limited circumstances you may be able to return a mistaken distribution to avoid the penalty, but the IRS treats that as an unusual exception rather than a routine fix.
FSA misuse works differently. Because the employer sponsors the plan, violations are handled administratively rather than through the tax code. Your plan administrator will contact you and require repayment of the ineligible amount. Repeated violations can result in account suspension or termination. There is no separate IRS penalty on top of repayment, but you lose the tax benefit on the repaid amount.