Administrator guide · checked August 2026

Letter of Medical Necessity for WEX

WEX’s own guidance is blunt: a gym membership is eligible "only if prescribed for a medical reason" — and the Letter of Medical Necessity is the document that records that prescription. Without it, WEX-administered plans deny gym claims as general wellness.

What WEX requires

  • The specific diagnosed condition, in writing
  • The prescribed expense (the membership or program), named
  • How the expense treats the condition, and for how long
  • The provider’s signature and license details

The steps, in order

  1. Get the letter first
  2. Pay the gym out of pocket and keep itemized receipts
  3. Submit the claim through your WEX benefits portal with letter + receipt
  4. Renew the letter annually while you keep claiming

Source: WEX: What is a Letter of Medical Necessity?. Policies change and employer plan designs vary — your administrator makes the final reimbursement decision. This page is general information, not tax or medical advice.

Need the letter itself?

A board-certified physician reviews your health profile and, when clinically appropriate, issues a signed Letter of Medical Necessity the same day — with the diagnosis, ICD-10 code, duration, NPI and license your administratorlooks for. $69, full refund if a letter isn’t issued. The eligibility check is free.

Check if I qualify →

Common questions

My employer’s plan is "administered by WEX" — does this apply to me?

WEX administers plans that employers design, and an employer can exclude gym reimbursement entirely. If your claim is denied despite a complete letter, ask whether the plan document excludes fitness expenses.

What makes a letter fail with WEX?

Vagueness. "Exercise is beneficial" fails; a named diagnosis, the named expense, a duration, and a real signature is the standard their reviewers look for.

Can MedSlip’s letter be verified?

Yes — every MedSlip letter carries the physician’s NPI, state license, and a QR verification code your administrator can check at medslip.co/verify.

Keep reading
The complete Letter of Medical Necessity guide (2026)Is a gym membership HSA/FSA eligible?What qualifies for an LMN: the full catalog