You can pay for a home sauna with pre-tax dollars. It takes one letter. I'm Brian Mitchell, Sauna Expert and Team Lead at The Sauna Place in Cookeville, Tennessee, and I bring this up with customers because it changes the math.
A letter of medical necessity for a sauna can reclassify your purchase from a personal expense to a qualified medical expense. Depending on your tax bracket, that single piece of paper can save you roughly 20 to 40 percent on a purchase that runs $2,500 to $13,000. Once you know the steps, it's straightforward.
Key Takeaways
- A home sauna can qualify as HSA/FSA-eligible medical equipment when a licensed clinician issues a Letter of Medical Necessity for a diagnosed condition (IRS Pub 502).
- Without that letter, FSA claims get denied and HSA spending risks tax plus a 20% penalty.
- Chronic pain, cardiovascular health conditions, and mental health diagnoses are common LMN reasons.
- Your letter needs a specific diagnosis and ICD-10 code, not just a general wellness recommendation.
- The template below gives your healthcare provider exactly what they need to get this done fast.
What a Letter of Medical Necessity Actually Does
Your HSA or FSA plan treats a sauna the same way it treats a hot tub or a swimming pool. Personal item. Not covered. A letter of medical necessity can make the sauna eligible. Your medical provider states in writing that sauna therapy is meant to alleviate symptoms of a diagnosed condition as part of your treatment plan. That letter tells your plan administrator this expense qualifies as a medical expense under IRS rules.
The IRS defines medical expenses under Publication 502 and IRC Section 213(d). A sauna qualifies when a licensed provider ties it to a specific medical condition. Without medical necessity documentation, it does not matter how real your condition is. It does not qualify.
A Letter of Medical Necessity is required, but it isn't a guarantee. The sauna has to be primarily for treating a diagnosed condition your clinician documents, and your plan administrator or the IRS can still disagree.
I tell customers the same thing. Get the letter first. Buy the sauna second.
Conditions That Qualify
Chronic pain and fibromyalgia are common reasons. The research is early and small, but customers managing daily pain tell us gentle heat helps. Cardiovascular conditions such as high blood pressure can qualify too, once your cardiologist documents the need and clears you for heat.
Rheumatoid arthritis and chronic fatigue syndrome come up too. Mental health conditions like depression and anxiety can qualify when heat exposure is part of a broader treatment plan. Skin conditions like psoriasis sometimes qualify. One caution: heat is not safe for everyone. Pregnancy, heart conditions, low blood pressure, and fever over 100.4F need a doctor's okay first.
What does not qualify: general wellness products. Stress relief without a diagnosed condition. Weight loss goals without a metabolic disorder. "Sauna is good for relaxation" gets denied. Your letter needs a specific recommended treatment tied to a real diagnosis. Your clinician decides, not us.
Which Sauna Types Are Eligible
The sauna type on your letter needs to match what you actually purchase. I have seen customers get denied because their LMN said "infrared sauna" and they bought a traditional sauna. That mismatch matters.
Small infrared studies focus on pain and circulation. The large cardiovascular studies on regular sauna bathing used traditional Finnish saunas1 (observational, men only). Either type can go on a letter. A hybrid sauna combining infrared and conventional heating qualifies too, as long as your provider specifies it.
Some plan administrators will also approve studio sessions, though many only cover durable home equipment. Red light therapy panels are a separate category entirely and need their own documentation. Don't assume they're bundled.
How to Get Your Letter: Five Steps
Step 1. Confirm your diagnosed condition exists in your medical records. If you have not been formally diagnosed, schedule that appointment first. Bring whatever supporting documentation you have about sauna therapy for your condition. Your provider may not know the connection.
Step 2. Ask your healthcare provider directly. MDs, DOs, NPs, and PAs can all sign a letter of medical necessity. Some plans accept chiropractors. Others do not. Check your plan rules before the appointment. Tell your provider exactly what you need: "I need a letter of medical necessity for infrared sauna therapy as part of my treatment plan for [your condition]."
Step 3. Make sure the letter covers every item on the checklist below, including a specific sauna use recommendation. Vague language kills these letters.
Step 4. Submit to your plan administrator. With an HSA, you determine HSA eligibility yourself and keep the LMN on file for a potential IRS audit. For an FSA, submit the LMN to your administrator. Many want it on file before you buy, so ask early.
Step 5. Buy your sauna and keep everything. The LMN, the receipt, the approval letter. IRS record retention runs a minimum of three years. I tell customers to keep it for seven.
Free LMN Template to Bring to Your Provider
Bring this to your appointment. Your provider fills in the medical parts, puts it on their own letterhead, and signs only if it's clinically justified. If your plan requires its own form, use that instead.
You fill in before the visit: your full name, date of birth, and the exact sauna type and model you plan to buy.
Your provider fills in: diagnosis and ICD-10 code, clinical rationale, frequency and duration, license, NPI, and signature.
[Provider Letterhead]
Date: [Date]
To Whom It May Concern:
I am writing to confirm that [Patient Full Name], DOB [Date of Birth], is under my care and was last evaluated on [Date of Exam]. [Patient Name] has been diagnosed with [Diagnosis / ICD-10 Code(s)].
Based on my clinical evaluation, I recommend [infrared / traditional / hybrid] sauna therapy, primarily to alleviate or treat [condition], as a medically necessary component of the patient's treatment plan. It is not for general wellness.
Equipment: [Sauna type and model]
Frequency and session length: [as determined by provider]
Duration of need: [as determined by provider]
[Provider Name], [Credentials]
License: [Number, State] | NPI: [Number]
[Practice Name] | [Phone for verification]
[Signature]
Checklist. Every LMN needs: a diagnosis with ICD-10 code, the words "medically necessary" and "primarily to treat [condition]", a sauna type that matches your purchase, frequency and duration, the provider's license, NPI, and signature, and a date within the last 12 months. Miss any of those and the letter fails.
HSA vs. FSA vs. HRA
Health savings accounts roll over year to year with no expiration. You control the account. You can buy directly and keep the LMN on file in case of audit. HSA custodians do not pre-approve purchases. That makes it the most straightforward of the three.
FSA is trickier. Funds run on a plan year. Your plan may allow a carryover (max $680 in 2026) or a grace period. Use it or lose it. Many FSA administrators want the LMN on file before you buy. Timing kills people on this one. I have talked to customers who missed their window by two weeks and lost the funds entirely.
HRA funding comes from your employer, and eligible categories vary by company. Submit your LMN per your employer's process and don't assume anything carries over from a previous plan.
Here's how you save money. A $5,000 sauna at a 30 percent marginal tax rate saves $1,500 in purchasing power. A $10,000 sauna saves $3,000 or more. Talk to a qualified tax adviser about your specific situation.
Common Reasons Letters Get Denied
- Vague language. "Recommended for health benefits" gets rejected. Specific diagnosis and treatment rationale get approved.
- Missing credentials. No NPI, license, or signature. Administrators can reject incomplete letters.
- Expired documentation. Many administrators require the LMN dated within 12 months. To keep your sauna LMN valid for ongoing use, renew annually.
Frequently Asked Questions
Is a sauna HSA eligible without a letter of medical necessity?
Not as a qualified expense, and a diagnosis alone doesn't make it automatically covered. The LMN makes it a medical expense under IRS rules. Without it, the spend is taxable, plus a 20% penalty under age 65.
How long does getting a letter take?
From your own doctor, usually one to two weeks. Telehealth LMN services can be faster, sometimes within days. Bring the template above. Coming prepared speeds things up.
Are sauna blankets and portable units HSA/FSA eligible?
Yes, same rules. Lower price, same process: a valid LMN naming the matching sauna type.
Does my employer see what I bought with FSA funds?
Your administrator reviews the LMN. Specific purchase details typically stay with the administrator. That said, plan rules vary, and I'm not your HR department. Check yours.
Will health insurance pay for a sauna?
Rarely. Health insurance plans almost never reimburse home equipment like a sauna. The realistic path is pre-tax HSA or FSA funds backed by an LMN.
How big are the tax savings, realistically?
At 25 percent, a $6,000 sauna effectively costs $4,500. At 35 percent, that same sauna runs $3,900. The letter of medical necessity is what makes that tax-free math possible. Worth a doctor's appointment.
This guide is general information, not medical or tax advice. Questions about which sauna fits your space or your payment options? Call our team at The Sauna Place at (931) 268-6545 or visit saunaplace.com.
Sources
1 Laukkanen JA et al., "Association Between Sauna Bathing and Fatal Cardiovascular and All-Cause Mortality Events," JAMA Internal Medicine, 2015 (2,315 Finnish men, about 20-year follow-up). IRS Publication 502, Medical and Dental Expenses. IRS Rev. Proc. 2025-32 (2026 health FSA carryover limit).
Disclaimer: This article is for informational purposes only and does not constitute medical advice. If you are pregnant, have cardiovascular conditions, heat sensitivity, or other health concerns, consult a qualified healthcare professional before using a sauna.