Yes, mouth guards are FSA eligible when they treat or prevent a dental or medical condition rather than serving general comfort or performance. Night guards for teeth grinding, oral appliances for sleep apnea, and athletic mouth guards used to prevent dental injury all qualify, provided you can document the medical purpose. Your plan administrator will decide based on the paperwork you submit, so the type of guard matters less than what your dentist or doctor puts in writing.
The rule comes from the federal tax code’s definition of “medical care.” Under 26 U.S.C. ยง 213(d), a qualified medical expense covers the diagnosis, treatment, or prevention of disease, and anything that affects a structure or function of the body.1Office of the Law Revision Counsel. 26 USC 213 – Medical, Dental, Etc., Expenses Mouth guards can fit that definition several different ways.
Which Types of Mouth Guards Qualify
Night Guards for Bruxism and TMJ
Night guards (also called occlusal guards) worn to treat bruxism or a temporomandibular joint disorder are the clearest case. They protect teeth from grinding damage and relieve jaw pressure, so they directly treat a diagnosed physical condition. The federal employees’ FSA program lists occlusal guards for teeth grinding as an eligible expense when submitted with a letter of medical necessity from your doctor and a detailed receipt.2FSAFEDS. Eligible Limited Expense Health Care FSA (LEX HCFSA) Expenses Most private-sector plans work the same way.
Athletic Mouth Guards
Athletic mouth guards can qualify when they are used to prevent dental injury or reduce concussion risk, not solely for athletic performance. Because the tax code covers prevention of disease and protection of body structures, a guard worn during contact sports serves a qualifying purpose.1Office of the Law Revision Counsel. 26 USC 213 – Medical, Dental, Etc., Expenses Some administrators still ask for documentation showing the medical purpose, so confirm with your plan before assuming automatic reimbursement.
Oral Appliances for Sleep Apnea
Oral appliances prescribed for obstructive sleep apnea, sometimes called mandibular advancement devices, are also eligible. They reposition the lower jaw to keep the airway open during sleep, which treats a diagnosed condition. You will need a prescription or letter of medical necessity from your physician or dentist.
Custom-Fitted vs. Over-the-Counter Guards
Both custom and over-the-counter guards can qualify, but the price gap is wide. A custom guard fabricated from dental impressions typically runs $300 to $800, and premium TMJ appliances can cost more. OTC boil-and-bite guards from a pharmacy or online retailer start around $20 to $50.
IRS Publication 502 confirms that amounts paid for the prevention and alleviation of dental disease count as medical expenses.3Internal Revenue Service. Publication 502 – Medical and Dental Expenses An OTC guard for bruxism falls under that umbrella, but the guard itself does not prove a diagnosis exists. A letter of medical necessity from your dentist handles that for both OTC and custom purchases.
Documentation You Need for Reimbursement
Letter of Medical Necessity
The letter of medical necessity is the single most important document. It should identify the patient, state the diagnosis (bruxism, TMJ disorder, sleep apnea, or similar), confirm that the device is medically necessary for that condition rather than for general wellness or cosmetic reasons, and give a treatment duration. A chronic condition can be listed as “lifetime.” Your licensed practitioner signs and dates the letter.4FSAFEDS. Letter of Medical Necessity Form
Itemized Receipt
Your receipt needs the date of service, the provider’s name, a description of the guard, and the amount you paid. If your dentist billed for other services at the same visit, the guard’s cost should appear as a separate line. A credit card statement alone will not do the job; administrators want an itemized bill.
Claim Form
Most administrators require a claim form with your participant ID, the type of expense, service dates, and the amount you are requesting. Names, dates, and dollar amounts on the form must match the receipt and letter exactly. Mismatches are one of the most common reasons claims come back rejected.
How to Pay and File
FSA Debit Card
If your plan issued a debit card and you buy the guard at a retailer using an Inventory Information Approval System, the system verifies the item as a medical expense at checkout and no follow-up paperwork is needed.5Internal Revenue Service. IRS Notice 2006-69 – Debit Card Substantiation Methods At a dentist’s office, which typically does not use that system, the charge is conditional. Your administrator will contact you later for the receipt and supporting documents.
Manual Reimbursement
If you pay out of pocket, submit a claim package to your administrator through their online portal or by mail. Upload scanned copies of the receipt, letter of medical necessity, and claim form. Once verified, most claims process within one to two business days, with reimbursement following shortly after, though timelines vary by administrator.6FSAFEDS. FAQs – Claim Processing Times
If Your Claim Is Denied
A denial is not the end of the road. Most denials come from missing documentation, a mismatch between the claim form and receipt, or an administrator who does not see a clear medical purpose. Read the denial notice, fix what was missing, and resubmit before filing a formal appeal.
If resubmission does not work, you can file a written appeal. A first-level appeal is a signed letter explaining why you disagree, backed by additional documents such as an updated letter of medical necessity. Administrators generally respond within 30 days. If that fails, you can request a second-level review, and some plans offer a final independent review by an outside arbitrator whose decision is binding. Check your plan documents for the deadlines that apply to your account.
2026 Contribution Limits and Year-End Timing
For the 2026 plan year, you can contribute up to $3,400 to a health care FSA through pre-tax salary reductions, a $100 increase over 2025.7Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026 Your employer may add funds on your behalf if the plan allows it.8Internal Revenue Service. Publication 969 (2025), Health Savings Accounts and Other Tax-Favored Health Plans
FSAs run on a use-it-or-lose-it basis. Unspent money at the end of the plan year is forfeited unless your employer offers one of two options (not both):9Internal Revenue Service. IRS – Eligible Employees Can Use Tax-Free Dollars for Medical Expenses
- A grace period of an extra two and a half months (typically until March 15 for a calendar-year plan) to incur eligible expenses.
- A carryover of up to $680 of unused funds into the 2026 plan year. Anything above $680 is forfeited.7Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026
A custom mouth guard can run several hundred dollars, so timing the purchase before your plan year ends is a practical way to spend funds that would otherwise disappear. Check your plan documents to see which option, if either, your employer offers.