Red light therapy is FSA eligible when a licensed provider prescribes it to treat a diagnosed medical condition, and it is not eligible when the purpose is cosmetic or general wellness. The device itself is neutral in the eyes of the IRS. What matters is the reason you’re buying it and whether you can document that reason.
The Rule That Decides Eligibility
FSAs reimburse “medical care” as defined in federal tax law. Under 26 U.S.C. § 213, that means amounts paid for the diagnosis, cure, mitigation, treatment, or prevention of disease, or for affecting a structure or function of the body.1Office of the Law Revision Counsel. 26 USC 213 – Medical, Dental, Etc., Expenses IRS Publication 502 adds that the expense must primarily alleviate or prevent a physical or mental illness; costs that are merely beneficial to general health don’t qualify.2Internal Revenue Service. Publication 502 (2025), Medical and Dental Expenses
The tax code also carves cosmetic procedures out of “medical care.” Section 213(d)(9) defines a cosmetic procedure as one directed at improving appearance that does not meaningfully promote the proper function of the body or treat illness or disease.1Office of the Law Revision Counsel. 26 USC 213 – Medical, Dental, Etc., Expenses Red light therapy sits right on that line, which is why documentation matters so much.
When Red Light Therapy Qualifies
A red light therapy device becomes an eligible medical expense when your doctor prescribes it for a specific diagnosed condition. Common examples include:
- Skin disorders such as psoriasis, eczema, or severe acne, where light therapy is a recognized treatment.
- Chronic pain and joint conditions, including arthritis and inflammatory musculoskeletal pain.
- Wound healing and post-surgical tissue repair, where the therapy is used to reduce inflammation and support recovery.
The cosmetic carve-out has one narrow exception. A procedure aimed at appearance can still qualify if it addresses a deformity from a congenital abnormality, an injury or trauma, or a disfiguring disease.1Office of the Law Revision Counsel. 26 USC 213 – Medical, Dental, Etc., Expenses Red light therapy prescribed for scarring caused by a disfiguring skin disease could fit here.
When It Doesn’t Qualify
Red light therapy bought for anti-aging, fine lines, general skin tone, relaxation, or overall wellness is not FSA eligible. The IRS test isn’t whether the device could theoretically help someone with a medical condition. It’s whether your purchase treats a diagnosed medical problem. The same device is eligible when prescribed for psoriasis and ineligible when bought to improve your complexion.
The Letter of Medical Necessity
Because red light therapy has both medical and cosmetic uses, your FSA administrator will almost certainly require a Letter of Medical Necessity (LMN) from a licensed provider before approving reimbursement. Get the letter before you buy the device. Submitting a claim without one is the single most common reason these claims are denied.
A usable LMN includes:
- Your name and the specific diagnosis being treated.
- A description of the red light therapy device or treatment being recommended.
- A statement explaining why the treatment is medically necessary for that condition, not merely helpful to general health.
- Your provider’s name, credentials, license information, and signature.
- A date current to the purchase.
Hold on to your itemized receipt as well. It should show the merchant, the date, a description of the device, and the amount paid. Your administrator may ask for both the LMN and the receipt when you file.
Paying With Your FSA
You have two ways to use FSA funds: the FSA debit card at checkout, or paying out of pocket and filing for reimbursement.
The debit card works cleanly at retailers that use an Inventory Information Approval System (IIAS), which checks eligibility at the point of sale. When the card runs through an IIAS-certified retailer, you often don’t need to submit a receipt at all. The catch with red light therapy is that many devices sell through specialty stores or direct-to-consumer websites that aren’t IIAS-certified. At those merchants, the card may be declined or flagged for follow-up documentation.
The alternative is to pay out of pocket, then upload your LMN and itemized receipt through your administrator’s portal or app. Processing times vary. Approved reimbursements usually arrive by direct deposit.
HSAs and HRAs Use the Same Standard
If you have an HSA or HRA rather than an FSA, the eligibility test is identical: all three account types use the § 213 definition of medical care.1Office of the Law Revision Counsel. 26 USC 213 – Medical, Dental, Etc., Expenses Prescribed red light therapy can be paid from any of them with the same documentation. A limited-purpose FSA, which is generally restricted to dental and vision expenses, typically won’t cover it.
If Your Claim Is Denied
Denials on red light therapy claims almost always trace back to documentation. Before you appeal, confirm that your submission included a current LMN with all the required details, an itemized receipt showing the device and amount, and a purchase date inside the active plan year.
If everything was in order and the claim was still denied, you can submit a written appeal to your plan administrator. Deadlines vary by plan; some require the appeal within 60 days of the initial decision, so check your plan documents. Strengthen the appeal with additional supporting material from your provider, such as medical records showing the diagnosis or a more detailed explanation of medical necessity. Your employer’s benefits or HR contact can point you to the plan’s summary description, which lays out any further review options if the appeal is denied.