This is the option most buyers overlook. Here’s how it actually works.

Why they’re not automatically eligible

HSA and FSA funds cover qualified medical expenses. A sauna or cold plunge bought for general wellness doesn’t qualify on its own — but if a licensed clinician documents it as medically necessary for a diagnosed condition, it can become eligible. That documentation is the Letter of Medical Necessity (LMN).

The process (via TrueMed)

1. Select “Pay with HSA/FSA” / TrueMed at checkout with a participating brand.
2. Complete a short health questionnaire; a licensed provider reviews it.
3. Receive an LMN (often within 24–48 hours) if approved.
4. Pay with your HSA/FSA card, or pay normally and submit the LMN + receipt to your administrator for reimbursement.

What to know before you rely on it

• It’s a tax-advantaged benefit, not a discount — you still pay, just with pre-tax dollars.
• Acceptance can vary by plan administrator.
• Generally only submit expenses dated on or after the LMN.
• Many major brands (e.g. Plunge, Sun Home, Redwood) participate — look for the TrueMed option.

What qualifies — and what to keep

Eligibility hinges on the Letter of Medical Necessity connecting the purchase to a diagnosed condition (for example, a clinician documenting cold or heat therapy for a specific recovery, pain, or cardiovascular-related need). Keep good records: the LMN itself, your itemized receipt, and any provider notes. As a general rule, only submit expenses dated on or after the LMN, since reimbursement is for medically-necessary costs from that point forward.

If a claim is questioned

Plan administrators differ in what they accept and how they review claims, so a request can occasionally be queried. Your best protection is documentation — a clear LMN and matching receipt — and contacting your administrator to understand their specific process before you buy. Because tax rules and plan terms vary, confirm the details with a tax professional and your HSA/FSA provider rather than assuming approval.

FAQ