What an HSA is, in plain English
A health savings account is a savings account that lets you set aside money before taxes to pay for qualified medical expenses. HealthCare.gov explains that you can use those untaxed dollars for costs such as deductibles, copayments, and coinsurance, which can lower your out-of-pocket health care costs.
Two HSA features matter most for planning. First, you can contribute only if you are enrolled in an HSA-eligible health plan, often called a high-deductible health plan. Second, the money rolls over from year to year and stays with you if you change jobs. IRS Publication 969 covers the detailed contribution and eligibility rules, and contribution limits change by year.
What an FSA is, in plain English
A flexible spending account, sometimes called a flexible spending arrangement, is an arrangement through an employer that lets you pay many out-of-pocket medical expenses with tax-free money. HealthCare.gov notes that employers may contribute to an FSA but are not required to.
The big difference from an HSA is timing. FSA money generally must be used within the plan year, although an employer may offer a grace period of up to two and a half extra months or a limited carryover. An FSA also cannot be used with a Marketplace plan, and FSA funds cannot be used to pay insurance premiums.
Weight-care costs that may qualify
Clinician visits, lab tests, and prescription medicines are generally treated as qualified medical expenses. That means HSA or FSA money can often be used for a weight-care visit, ordered lab work, or a prescribed medicine, as long as the expense meets plan and IRS rules.
Weight-loss program fees follow a stricter rule. IRS Publication 502 says you can include amounts you pay to lose weight only if the weight loss is treatment for a specific disease diagnosed by a physician, such as obesity, hypertension, or heart disease. When that condition is met, the includible amounts can cover membership fees in a weight-reduction group and fees for attending periodic meetings.
Costs that usually do not qualify
IRS Publication 502 is also clear about common exclusions. You cannot include membership dues for a gym, health club, or spa as medical expenses, although separate fees charged there for weight-loss activities may count. You cannot include the cost of diet food or beverages, because they substitute for what is normally consumed to satisfy nutritional needs.
Programs aimed only at improving appearance, general health, or a sense of well-being do not qualify either. If the weight-loss treatment is not for a specific disease diagnosed by a physician, the related program fees cannot be counted as medical expenses.
How to check before you pay
Before paying for a weight-care program with HSA or FSA money, read your plan documents or call the plan administrator and ask whether the specific expense is eligible. Ask the program for itemized receipts that show what you paid for, because a single bundle price can mix qualifying and non-qualifying items.
If a program fee depends on a diagnosed condition, ask your clinician how that diagnosis is documented in your records. Keep receipts, documentation, and plan confirmations together. For anything unclear, check IRS Publication 502 or talk with a tax professional, because this site explains questions and boundaries but does not give tax advice.