How to Pay for Your Gym With HSA/FSA Money: A Doctor's Step-by-Step Guide for 2026

Adam Z. Kawalek, MD

June 4, 2026 · 6 min read

If you’ve confirmed that a medically necessary gym membership can be HSA/FSA eligible, the next question is the practical one: how do you actually do it without getting your claim bounced? Here’s the step-by-step I give patients.

Step 1 — Confirm you have a qualifying condition

Eligibility starts with a diagnosed condition that exercise helps treat — obesity, hypertension, type 2 diabetes or prediabetes, high cholesterol, heart disease, or a similar issue. You don’t need to have been formally treated for it for years; you need a physician to review your situation and confirm the diagnosis applies. Many adults qualify on something they didn’t realize counted.

Step 2 — Get a Letter of Medical Necessity

This is the document that does the work. A physician reviews your case and, if appropriate, issues a signed LMN naming your condition, confirming exercise as treatment, and stating the duration. MedSlip handles this entirely online — you answer a few health questions, a board-certified physician reviews them, and you receive the signed letter, usually the same day. No clinic visit, and no charge if a letter can’t be issued.

Step 3 — Choose how you’ll pay or get reimbursed

You have two routes. If your HSA/FSA debit card is accepted by the gym, you can pay directly and keep the LMN on file in case of an audit. More often, you’ll pay out of pocket and submit a reimbursement claim to your plan administrator, attaching the LMN and your gym receipts. Both are valid — reimbursement is just the more common path for recurring memberships.

Step 4 — Submit the claim with the right attachments

When you file, include: the Letter of Medical Necessity, an itemized receipt or statement showing the membership cost and dates, and your plan’s reimbursement form if it has one. Administrators approve claims far faster when the LMN and receipts arrive together — a missing letter is the single most common reason a gym claim gets held up.

Step 5 — Keep records and renew annually

Save your LMN and receipts for at least three years in case of an IRS or plan audit — the documentation is what protects the tax treatment. Because most letters are valid for 12 months, set a reminder to renew yours each plan year so your reimbursements never lapse.

Common mistakes that get claims denied

• Submitting receipts with no Letter of Medical Necessity attached
• Using a letter that names no specific condition (“exercise is healthy” isn’t enough)
• Letting the 12-month letter expire mid-plan-year
• Trying to reimburse a membership bought purely for general fitness, with no diagnosed condition
• Not keeping the paperwork after the claim is approved

Avoid those five and the process is genuinely straightforward. The hardest part — getting a proper Letter of Medical Necessity — is the part MedSlip was built to make easy. Once you have it, your gym becomes one more pre-tax expense working in your favor.

Adam Z. Kawalek, MD

Board-Certified Physician · Founder, MedSlip · Cedars-Sinai · Johns Hopkins

Dr. Kawalek is a board-certified internal medicine physician with 15+ years of clinical experience. He founded MedSlip to give patients fast, affordable access to the Letters of Medical Necessity that make fitness and wellness spending HSA/FSA-eligible.