Sauna, E-Bike, Oura Ring, Mattress: What Else Is HSA/FSA Eligible in 2026? (Doctor's Guide)

Adam Z. Kawalek, MD

August 27, 2026 · 7 min read

Most people know a gym membership can become HSA/FSA eligible with the right documentation. Far fewer know the same IRS rule covers a much longer list: saunas, e-bikes, health wearables, mattresses, air purifiers, red light therapy, even mobility scooters. Our patients kept asking about these, so as of this week we issue letters for all of them. Here is what qualifies, and why.

The rule that makes any of this work

IRS Section 213(d) and Publication 502 define medical care as amounts paid for the diagnosis, cure, mitigation, treatment, or prevention of disease. A product that serves both general wellness and medical treatment is called a dual-purpose expense. It becomes reimbursable only when a licensed physician documents that, for you, it treats a specific diagnosed condition. That documentation is a Letter of Medical Necessity (LMN). No letter, no eligibility. With one, the purchase can be made or reimbursed with pre-tax dollars.

Health wearables: Oura, Whoop, Apple Watch

Continuous heart-rate, activity, and sleep tracking supports the management of several diagnosed conditions: high blood pressure, prediabetes and type 2 diabetes, diagnosed sleep disorders, weight management, and atrial fibrillation, where an ECG-capable wearable supports rhythm monitoring. If one of these applies to you, a physician can document the device as part of your care. See if your wearable qualifies.

Saunas and cold plunges

Regular heat therapy has evidence for reducing musculoskeletal pain and stiffness, and sauna bathing is associated with lower blood pressure in prospective studies. A sauna or cold plunge can be documented for chronic back or joint pain, high blood pressure, or low mood as an adjunct to standard care. See if a sauna qualifies for you.

Mattresses and sleep systems

A supportive, pressure-redistributing sleep surface can be documented for chronic back pain. Inclined reflux-relief systems address nighttime GERD. Weighted blankets have trial evidence in anxiety. Diagnosed insomnia supports sleep-environment optimization. See if a mattress or sleep system qualifies.

Air purifiers and humidifiers

Reducing indoor airborne allergens and irritants is a recommended environmental-control measure for asthma, allergic rhinitis, and COPD, and humidification supports symptom control in chronic sinusitis. If a clinician has diagnosed one of these, a HEPA purifier or humidifier can be documented as treatment. See if an air purifier qualifies for you.

Red light therapy

Photobiomodulation has randomized-trial evidence for short-term pain reduction in osteoarthritis and as an adjunctive treatment for inflammatory acne. See if red light therapy qualifies.

E-bikes

An e-bike is exercise equipment under the same logic as a stationary bike: prescribed aerobic activity for conditions like weight management, high blood pressure, prediabetes or type 2 diabetes, high cholesterol, joint or back pain, low mood, anxiety, or diagnosed sleep conditions. The assist motor is what makes prescribed activity sustainable for many patients. See if an e-bike qualifies for you.

Mobility scooters

When severe arthritis, peripheral neuropathy, or COPD limits safe walking, a powered mobility device preserves independence and community participation. This is classic medical necessity territory, and a letter documents it for your administrator. See if a mobility scooter qualifies.

What does not qualify

No physician letter can make a general-wellness purchase eligible without a real diagnosed condition behind it. We decline those requests and refund the fee. Prescription medications follow a different path entirely (they need a prescription, not an LMN), and some items, like CPAP machines prescribed for sleep apnea, are already eligible without any letter. If you are unsure which bucket your purchase falls in, the intake sorts it out before you pay.

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.