Paying for prescriptions with an HSA or FSA: a complete guide

The two accounts at a glance

A health savings account, or HSA, is available only to people covered by a qualifying high-deductible health plan who have no other disqualifying coverage and are not enrolled in Medicare. Since January 1, 2026, a bronze or catastrophic plan available as individual coverage through a Health Insurance Marketplace also counts as a qualifying plan, under IRS Notice 2026-5. Contributions go in before tax or are deductible, the balance grows without tax, and withdrawals for qualified medical expenses are tax-free. The account belongs to you, so it stays with you if you change jobs, and unused money rolls over indefinitely; if your HSA provider offers investments, part of the balance can be invested for future medical costs.

A health flexible spending account, or FSA, is offered through an employer, whatever kind of health plan you have. You choose an amount to set aside from your pay before tax, and the full annual amount must be available for eligible expenses from the first day of the plan year. Money left at the end of the year is generally forfeited, unless your employer offers either a short grace period or a limited carryover into the next year. The IRS sets annual contribution limits for both accounts, which rise most years; your plan administrator or the IRS can confirm the current figures.

What counts as an eligible prescription expense

Both accounts can pay for medicines prescribed for you, your spouse and your tax dependents. Insulin is eligible even without a prescription. Since the CARES Act of 2020, over-the-counter medicines, such as pain relievers, allergy tablets, antacids and cold remedies, are eligible without a prescription, as are menstrual care products. Supplies such as glucose test strips, syringes and continuous glucose monitors are eligible too.

Things that do not count include medicines for pets, cosmetic products, and general health items such as vitamins taken for general wellbeing, unless a clinician has recommended them to treat a specific condition. Drugs imported in ways that break federal law are not eligible either. IRS Publication 502 is the authoritative list.

Paying at the pharmacy

If your HSA or FSA provider issues a debit card, you can use it at the pharmacy. You can use the card for an insurance copay or for a pharmacy’s own cash price; the account cares only that the purchase is an eligible medical expense, not how the price was set. If you pay another way, you can reimburse yourself from the account later, keeping the receipt.

That makes the accounts a natural fit with comparing cash prices. If a pharmacy’s cash price for a prescription is lower than your plan’s price, paying it from an HSA or FSA means both the lower price and pre-tax money. Remember that a cash purchase made outside your insurance counts toward your deductible only if your plan accepts the receipt, which matters on a high-deductible plan.

Preventive drugs covered before the deductible

High-deductible plans generally cannot pay for care before the deductible is met, with exceptions that include preventive care and telehealth, and IRS guidance allows them to cover certain medicines for chronic conditions as preventive care from the first dollar. The list includes drugs such as statins, ACE inhibitors and beta blockers for heart conditions, metformin and insulin for diabetes, and SSRIs for depression, along with some tests and devices. Plans choose whether to use this option, so ask yours which drugs it covers before the deductible; for those drugs, compare your plan’s price with cash quotes from the first fill.

Records, deadlines and taxes

Keep pharmacy receipts or an itemized history showing the patient, the drug, the date and the amount paid. FSA administrators may ask for this to substantiate a card purchase, and with an HSA you are responsible for showing the IRS that withdrawals paid for qualified expenses if asked. An HSA withdrawal for something that is not a qualified medical expense is taxed and, before age 65, also carries an extra tax penalty.

FSA deadlines are the main trap: plan your annual election around medicines you know you will need, and check your employer’s grace period or carryover rule before the year ends. If money is left near the end of the plan year, eligible over-the-counter items you use regularly are one way to spend it before it is forfeited.

• Keep every pharmacy receipt, or download the pharmacy’s annual statement.
• Check your FSA’s year-end grace period or carryover rule.
• Use the HSA only for qualified expenses, or expect tax and a penalty.
• Ask your plan which preventive drugs it covers before the deductible.
• Remember that HSA contributions stop once you enroll in Medicare.

Planning your election and using the money well

To choose an FSA amount, start from last year’s pharmacy history: the refills you know you will need, expected copays or cash prices, and the over-the-counter items you buy regularly. Under the tax rules for these plans, you can generally change the election during the year only after a qualifying life event, such as marriage or the birth of a child, so leave a margin rather than guessing high.

With an HSA, there is no deadline for reimbursing yourself. If you pay a qualified expense out of pocket after the account was opened and keep the receipt, you can withdraw the same amount tax-free years later, which lets the balance stay invested in the meantime. Good records make that possible.

Combining accounts and special cases

If you have an HSA, you generally cannot also have a general-purpose health FSA, but you can have a limited-purpose FSA for dental and vision costs, which keeps the HSA for prescriptions and other medical bills. A dependent care FSA is a different account for childcare and cannot pay for medicines. If you are approaching Medicare age, note that you can keep spending an existing HSA balance on qualified expenses, including Medicare premiums other than Medigap, after you stop contributing.