If you're researching home saunas and wondering whether you can put your Health Savings Account or Flexible Spending Account to work on the purchase, here's the short answer: yes, saunas are HSA and FSA eligible — but only when you have a Letter of Medical Necessity (LMN) from a licensed healthcare provider.
That single document is the key that turns a sauna from a "wellness product" in the eyes of the IRS into a qualified medical expense you can pay for with pre-tax dollars. When done correctly, using HSA or FSA funds can reduce the effective cost of your sauna by 30–40%, depending on your tax bracket. On a $4,000 infrared sauna, that's potentially $1,200–$1,600 back in your pocket.
This guide covers exactly how the IRS treats sauna purchases, what qualifies you for an LMN, how the process works at Haven of Heat through our partnership with TrueMed, and everything else you need to know to make an informed decision.
Why Saunas Aren't Automatically HSA/FSA Eligible
HSAs and FSAs exist to help you pay for qualified medical expenses with pre-tax money. The IRS defines those expenses in Publication 502 as costs related to "the diagnosis, cure, mitigation, treatment, or prevention of disease." That publication provides a long list of items that clearly qualify — things like prescription medications, hearing aids, CPAP machines, and physical therapy.
Saunas are not on that list. By default, the IRS classifies them as general wellness or lifestyle products — the same category as gym memberships, massage chairs, and exercise equipment. Expenses that are merely "beneficial to general health" don't qualify, even if the health benefits are well-documented.
However — and this is the important part — Publication 502 is not an exhaustive list. The IRS allows expenses not specifically listed as long as they meet the core requirement: the expense must be "primarily for the prevention or alleviation of a physical or mental disability or illness," and a licensed healthcare provider must recommend it for that purpose. This is where the Letter of Medical Necessity comes in.
What Is a Letter of Medical Necessity?
A Letter of Medical Necessity (LMN) is a formal document from a licensed healthcare provider — a physician, nurse practitioner, or other qualified clinician — that establishes why a specific product or treatment is medically necessary for you as an individual. It's not a prescription in the traditional sense, but it functions similarly for HSA/FSA purposes.
For a sauna purchase to qualify, an effective LMN should include:
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Your diagnosed medical condition — the specific condition or conditions that sauna therapy will address
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Clinical rationale — an explanation of how regular sauna use will treat, mitigate, or prevent the progression of that condition
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A treatment recommendation — the recommended frequency and duration of sauna sessions as part of your care plan
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Proper medical coding — ICD-10 codes that correspond to your diagnosis, which HSA/FSA administrators use to process claims
- The provider's credentials and signature
The quality of your LMN matters. A vague letter that says "sauna use is recommended for general health" won't pass muster with most plan administrators. The letter needs to tie the sauna directly to a diagnosed medical condition with specific clinical reasoning.
Medical Conditions That Commonly Qualify
The IRS doesn't publish a specific list of conditions that make sauna therapy eligible. Instead, the standard is whether a licensed provider can establish medical necessity for your individual situation. That said, the following conditions are among the most commonly supported by clinical research and frequently cited in Letters of Medical Necessity for sauna purchases:
Cardiovascular conditions — Hypertension, congestive heart failure risk factors, and poor circulation are among the most well-researched applications of sauna therapy. A landmark Finnish study published in JAMA Internal Medicine found that frequent sauna use was associated with significantly reduced risk of fatal cardiovascular events. Many cardiologists now recognize regular sauna bathing as a complementary cardiovascular intervention.
Chronic pain and musculoskeletal disorders — Fibromyalgia, rheumatoid arthritis, osteoarthritis, chronic lower back pain, and other persistent pain conditions respond well to heat therapy. Infrared saunas in particular deliver deep-penetrating heat that reaches joints and muscle tissue without the extreme ambient temperatures of traditional saunas, making sessions more comfortable for people with pain conditions.
Mental health conditions — Depression, anxiety disorders, chronic stress, and PTSD are increasingly recognized as conditions where sauna therapy can play a supporting role. Research has shown that whole-body hyperthermia can produce antidepressant effects, and the relaxation response triggered by regular sauna use can help regulate the nervous system over time.
Metabolic conditions — Type 2 diabetes, insulin resistance, and metabolic syndrome are areas of active research. Some studies suggest that regular infrared sauna use may improve insulin sensitivity and support blood sugar regulation.
Respiratory conditions — Chronic obstructive pulmonary disease (COPD), asthma, and chronic bronchitis may benefit from the warm, humidified air environment of a traditional sauna. Steam from water poured over sauna heater stones can help open airways and support respiratory function.
Post-injury and post-surgical recovery — When recommended by a treating physician as part of a rehabilitation protocol, sauna therapy can support faster recovery through improved circulation and reduced inflammation.
Autoimmune conditions — Conditions like lupus, Hashimoto's thyroiditis, and other autoimmune disorders where inflammation management is central to treatment may qualify when a provider establishes the clinical connection.
This list is not exhaustive. If you have a medical condition that your healthcare provider believes would benefit from regular heat therapy, a sauna purchase may be eligible regardless of whether the condition appears on a list.
HSA vs. FSA: Key Differences That Affect Your Sauna Purchase
Both HSAs and FSAs allow you to pay for qualified medical expenses with pre-tax dollars, but they work differently in ways that matter when you're making a larger purchase like a home sauna.
Health Savings Account (HSA)
An HSA is a tax-advantaged savings account available to individuals enrolled in a High-Deductible Health Plan (HDHP). You own the account, and it stays with you even if you change employers or retire. For 2025, the IRS allows contributions of up to $4,300 for self-only coverage or $8,550 for family coverage, with an additional $1,000 catch-up contribution for individuals 55 and older. For 2026, those limits increase to $4,400 (individual) and $8,750 (family).
The biggest advantage for sauna buyers: HSA funds roll over indefinitely. There's no "use it or lose it" deadline. If you've been contributing to your HSA for several years, you may have accumulated enough to cover a significant portion — or all — of a home sauna purchase. You can also invest HSA funds for long-term growth, similar to a retirement account.
Flexible Spending Account (FSA)
An FSA is offered through your employer as part of your benefits package. For 2025, you can contribute up to $3,300 per year; for 2026, that limit rises to $3,400. Unlike an HSA, the account belongs to your employer — if you leave your job, you typically forfeit any unused balance.
The critical detail with FSAs is the "use it or lose it" rule. Most FSA funds expire at the end of the plan year. Some employers offer a grace period of up to 2.5 extra months, and others allow a carryover of up to $660 (2025) or $680 (2026) into the following year — but the majority of your balance will be forfeited if unspent. This makes FSAs particularly interesting for sauna buyers approaching year-end with unused funds. Rather than losing that money, applying it toward a medically necessary sauna purchase is a smart use of pre-tax dollars that would otherwise disappear.
Can You Use Both?
In most cases, you cannot have both a general-purpose healthcare FSA and an HSA simultaneously. However, you may be able to pair an HSA with a Limited-Purpose FSA (LPFSA), which covers only dental and vision expenses. If your sauna purchase exceeds the balance available in a single account, you can apply a partial reimbursement and pay the remainder out of pocket or with a regular payment method.
How Much Can You Actually Save?
When you use HSA or FSA funds for a qualified medical expense, you're paying with money that was never taxed. The savings depend on your combined tax bracket — federal income tax, state income tax, and FICA taxes (Social Security and Medicare).
For most households, the effective savings range from 30% to 40% of the purchase price. Here's a practical example:
Suppose you're purchasing a home infrared sauna for $3,500. If your combined federal and state marginal tax rate is 32% and you add in the 7.65% FICA contribution, you're looking at a total tax savings of approximately $1,190–$1,390. That means the effective out-of-pocket cost drops to roughly $2,100–$2,300 in post-tax dollars — a meaningful reduction on what is already a long-term investment in your health.
For higher-ticket purchases like outdoor traditional saunas or premium cabin saunas, the tax savings can easily exceed $2,000–$5,000.
Do All Types of Saunas Qualify?
Yes. The type of sauna does not determine HSA/FSA eligibility — medical necessity does. Whether you're purchasing a traditional Finnish sauna, an infrared sauna, a hybrid model, or even a sauna blanket, the purchase can qualify as long as it's supported by a valid LMN. Here's how the most common types fit into the picture:
Infrared saunas are the most frequently purchased sauna type using HSA/FSA funds. Their lower operating temperatures (typically 120°F–150°F) make them accessible for people with pain conditions, cardiovascular concerns, or heat sensitivity, and the deep-penetrating infrared heat is directly relevant to many LMN clinical rationales. We carry FAR infrared and full spectrum infrared models from brands like Dynamic Saunas, Maxxus, Finnmark Designs, Golden Designs, and Peak Saunas.
Traditional saunas — including indoor cabin saunas, barrel saunas, and custom sauna room kits — also qualify when supported by an LMN. The cardiovascular research on sauna therapy, including the widely cited Finnish studies, was conducted primarily using traditional high-heat saunas.
Hybrid saunas that combine a traditional electric heater with infrared panels qualify as well. These models are popular because they give you both heating methods in a single unit, which can be particularly relevant when your LMN recommends varying heat protocols.
Portable saunas and sauna blankets can qualify if prescribed and documented in an LMN. These are often a good option for people with limited space or lower budgets who still need medically necessary heat therapy.
What About Cold Plunges?
Cold plunge tubs and ice baths can also be HSA/FSA eligible under the same framework — they require a separate Letter of Medical Necessity establishing that cold water therapy (hydrotherapy) is medically necessary for your specific condition. Conditions like chronic inflammation, post-surgical recovery, certain autoimmune conditions, and athletic recovery-related injuries are commonly cited.
Many of our customers invest in both a sauna and a cold plunge for contrast therapy — alternating between heat and cold exposure — which has growing clinical support for cardiovascular health, immune function, and recovery. If your provider determines that contrast therapy is medically necessary, both purchases may qualify.
How to Buy a Sauna With HSA/FSA Funds at Haven of Heat
We've partnered with TrueMed to make the process of using your HSA or FSA funds straightforward. TrueMed works with a network of licensed healthcare providers who can evaluate your eligibility and issue a compliant Letter of Medical Necessity. Here's how it works step by step:
Step 1: Choose your sauna. Browse our collections — indoor saunas, outdoor saunas, infrared saunas, or our top picks for 2026 — and add the sauna you want to your cart.
Step 2: Select TrueMed at checkout. During the payment step, choose the "TrueMed – Pay with HSA/FSA" option. This is available to U.S. residents only.
Step 3: Complete the eligibility questionnaire. TrueMed will guide you through a short, secure health questionnaire. Based on your responses, their licensed medical team will determine whether you qualify for a Letter of Medical Necessity.
Step 4: Receive your LMN and pay. If you qualify, your LMN is issued and you can complete the purchase using your HSA or FSA debit card. Alternatively, you can pay with a regular credit card and submit for reimbursement from your HSA or FSA provider afterward — just include your receipt and LMN with the claim.
Step 5: Keep your documentation. Save your LMN, receipt, and any correspondence with your HSA/FSA administrator. These records are important for your files in case of an IRS audit or administrator review.
The entire process typically takes just a few minutes during checkout. If you have questions at any point, our team is available by phone or text at (360) 233-2867.
What If You Don't Have Enough HSA/FSA Funds to Cover the Full Purchase?
You don't need to cover the entire purchase with HSA or FSA funds. Partial reimbursement works perfectly. For example, if your sauna costs $3,500 and you have $2,000 in your HSA, you can apply the $2,000 in pre-tax funds and pay the remaining $1,500 with a regular payment method. You'll still save on the portion paid with HSA/FSA dollars.
We also offer 0% APR financing for up to 6 months through Shop Pay, which can be combined with partial HSA/FSA reimbursement to make the purchase even more manageable.
Important: Get Your LMN Before You Buy
Timing matters. HSA and FSA expenses are only eligible from the date your Letter of Medical Necessity is issued forward. If you purchase a sauna before obtaining your LMN, your administrator may reject the reimbursement claim. The safest approach is to have your LMN in hand — or to go through the TrueMed process at checkout — before completing the transaction.
If you already own a sauna and want to seek reimbursement retroactively, this generally won't work unless you had an LMN dated on or before the purchase date. Some administrators are more flexible than others, but the standard practice is to require the LMN to precede or coincide with the expense.
What If Your Claim Gets Denied?
Claim denials can happen, and they aren't always the end of the road. Common reasons for denial include an incomplete or vaguely worded LMN, missing documentation, or the administrator not recognizing the expense category. If you're denied:
Contact your plan administrator to understand the specific reason. Ask what documentation they need to reconsider the claim.
Update your LMN if necessary. If the denial was due to insufficient clinical detail or missing ICD-10 codes, your healthcare provider (or TrueMed's team) can often revise and resubmit the letter. TrueMed offers a reimbursement guarantee for purchases made through their platform at partner merchants like Haven of Heat — they'll work with you to ensure your purchase is reimbursed as long as you have funds in your account.
File an appeal. Most HSA and FSA administrators have a formal appeals process. Include your updated LMN, supporting clinical research, and a clear explanation of the medical necessity.
A Note on IRS Scrutiny and Compliance
It's worth being transparent about the regulatory landscape. In March 2024, the IRS issued a public alert warning consumers about companies that misrepresent general wellness expenses as qualified medical expenses. The alert specifically called out businesses that offer "doctor's notes" based solely on brief self-reported questionnaires, without a genuine clinical evaluation, as a way to make non-medical purchases appear eligible.
This doesn't mean sauna purchases are under a cloud — it means the IRS expects the Letter of Medical Necessity to reflect a real clinical determination, not a rubber stamp. A legitimate LMN is one where a licensed provider has actually evaluated your health information and concluded, based on clinical judgment, that sauna therapy is medically appropriate for your condition. That's exactly what happens through the TrueMed process and through traditional doctor visits.
The distinction the IRS draws is between using pre-tax funds for genuine medical purposes (which is exactly what HSAs and FSAs were designed for) versus using them for general wellness or lifestyle purchases that don't address a specific medical condition. As long as you have a real medical need and proper documentation, you're on solid ground.
FSA Year-End Strategy: Don't Lose Your Funds
If you have an FSA with unused funds approaching the end of your plan year, a medically necessary sauna purchase is one of the smartest ways to put that money to work before it expires. Here's why:
Most FSA balances expire on December 31 (or at the end of your employer's plan year), with only a limited grace period or carryover amount preserved. Every dollar you don't spend is a dollar you lose. If you qualify for an LMN and have been considering a sauna, applying your expiring FSA funds to the purchase means you're converting money that would otherwise vanish into a tangible asset that supports your health for years to come.
Planning ahead is important here. Don't wait until December 30 to start the process. Begin evaluating your FSA balance, researching sauna options, and confirming your eligibility at least a few weeks before your plan year deadline so everything processes smoothly.
Can You Also Deduct a Sauna as a Medical Expense on Your Taxes?
Potentially, yes — but you can't double-dip. If you pay for a sauna with HSA or FSA funds, you've already received the tax benefit and cannot also deduct the same expense on your tax return. However, if you pay out of pocket (not through an HSA or FSA), you may be able to include the sauna as an itemized medical deduction on Schedule A of your federal tax return, provided you have an LMN and your total medical expenses exceed 7.5% of your adjusted gross income. Consult a tax professional for guidance specific to your situation.
Frequently Asked Questions
Do I need a prescription to buy a sauna?
No. Anyone can purchase a sauna at any time. The Letter of Medical Necessity is only required if you want to pay with HSA/FSA funds or seek reimbursement from those accounts.
Does the sauna need to be a specific brand or type to qualify?
No. The IRS doesn't distinguish between sauna brands, types, or heating methods. What matters is that your healthcare provider has established medical necessity for heat therapy. Whether you choose an infrared sauna or a traditional sauna, eligibility is determined by your medical situation, not the product specifications.
Can I use HSA/FSA funds for sauna accessories?
Generally, no. Accessories like buckets, ladles, aromatherapy kits, and thermometers are not medical devices and won't be covered. The HSA/FSA eligibility applies to the sauna unit itself — the equipment that delivers the therapeutic heat your LMN prescribes.
What if I don't have an HSA or FSA?
If you don't currently have one, you may be able to open an HSA during your next open enrollment period (if you're eligible for a High-Deductible Health Plan) or ask your employer about FSA options. Contributing to these accounts during the next enrollment period and then using the funds toward a sauna purchase is a viable strategy. Keep in mind that HSA funds can be used for expenses incurred in the current year or carried forward for future use, while FSA funds typically must be used within the plan year.
Is there a limit to how much I can spend on a sauna with HSA/FSA funds?
There's no spending limit on individual qualified medical expenses. The limit is on annual contributions to your account. If you've accumulated funds over multiple years in an HSA, you can apply the full balance to a single sauna purchase. FSAs are limited to the current year's contribution (up to $3,400 for 2026), but partial reimbursement is always an option.
Can I buy a sauna for more than one person and still use HSA/FSA funds?
The LMN is issued for your individual medical needs. While a multi-person sauna can certainly be used by your family, the HSA/FSA reimbursement is based on your medical necessity. Some administrators may note that saunas "intended for more than one person" are for personal use — but in practice, the size of the unit is secondary to whether the therapy is prescribed for you. Your LMN and your provider's recommendation are the determining factors.
Does the TrueMed process cost anything?
The eligibility evaluation and LMN issuance through TrueMed are included as part of the checkout process at Haven of Heat. There's no separate fee to you for the evaluation.
Ready to Explore Your Options?
If you're considering a home sauna and want to put your HSA or FSA funds to work, start by exploring the sauna that fits your space, goals, and budget. Our best indoor saunas guide and infrared sauna buyer's guide are great starting points. When you're ready, the TrueMed integration at checkout makes the HSA/FSA payment process seamless.
Have questions about which sauna is right for you, or need help navigating the HSA/FSA process? Our Oregon-based team is available by phone or text at (360) 233-2867 — we're happy to walk you through it.
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