Standard toothbrushes are not FSA eligible. The IRS treats toothbrushes, toothpaste, and regular floss as personal-use items rather than medical expenses, and Publication 502 lists them as nondeductible.1Internal Revenue Service. Publication 502 (2025), Medical and Dental Expenses The one way around this is a Letter of Medical Necessity from a dentist or physician stating that a specific toothbrush is needed to treat a diagnosed condition. Without that letter, the purchase doesn’t qualify, whether the brush is manual or electric.
Why the IRS Excludes Toothbrushes
The IRS draws a line between items that treat a specific medical condition and items you’d use anyway for general health. Toothbrushes sit on the general-health side. Publication 502 uses toothbrushes and toothpaste as its example of a nondeductible personal expense, and FSA plans follow the same rule.1Internal Revenue Service. Publication 502 (2025), Medical and Dental Expenses Everyone brushes their teeth, so the expense is considered upkeep, not care.
The same reasoning covers regular toothpaste, basic dental floss, and standard replacement heads for electric brushes. None of them treat a diagnosed condition on their own, so none of them pass the test. This trips people up when they see other oral-care items stocked at FSA-eligible retailers and assume the whole aisle qualifies. It doesn’t.
When a Toothbrush Can Qualify
A Letter of Medical Necessity changes the classification. If a dentist or physician determines that a specific toothbrush is needed to treat a diagnosed condition, the letter converts the purchase from personal to medical. This comes up for patients recovering from oral surgery, managing severe gum disease, or dealing with a condition that makes standard brushing ineffective or harmful.
The letter has to include the diagnosis, the specific product being recommended, and an explanation of why it’s necessary for treatment rather than general hygiene. A vague note saying the patient “should use an electric toothbrush” won’t clear an FSA administrator’s review. The letter also needs to make clear that the item isn’t being recommended for cosmetic reasons or general wellness.
Electric toothbrushes are the most common candidates, and some manufacturers provide template letters for dentists because the situation is so routine. Water flossers work the same way: not eligible on their own, but eligible with a Letter of Medical Necessity and a detailed receipt.2FSAFEDS. Eligible Health Care FSA (HC FSA) Expenses
Keep a copy of the letter with your tax records. Your FSA administrator may ask for it when you submit a claim, and some plans require the letter to be renewed each plan year for ongoing purchases.
Dental Expenses That Qualify Without a Letter
Plenty of dental costs are FSA eligible on their own, because their medical purpose is built in. You don’t need a Letter of Medical Necessity for any of these, just receipts and any explanation-of-benefits statements from your dental insurance.1Internal Revenue Service. Publication 502 (2025), Medical and Dental Expenses
- Orthodontic treatment, including braces, retainers, and clear aligners, because they correct structural problems with teeth or the jaw.
- Restorative work such as fillings, crowns, bridges, and dentures.
- Dental implants when they replace missing teeth or prevent bone loss from a medical condition, though not when placed purely for cosmetic reasons.
- Diagnostic and preventive services including X-rays, exams, and cleanings.
- Surgical procedures such as extractions, root canals, and periodontal surgery, along with any copayments or deductibles you pay toward them.
- Mouthguards prescribed for teeth grinding or jaw disorders.
Over-the-Counter Dental Products That Qualify
The CARES Act made over-the-counter medicines FSA eligible without a prescription in 2020.3FSAFEDS. FAQs – All Over-the-Counter (OTC) Medicines or Drugs That change reaches several dental products.
Toothache pain relievers, teething gels, and canker sore treatments qualify as OTC medicines. Medicated mouth rinses containing active drug ingredients qualify too. These treat a specific symptom or condition, which puts them on the medical side of the IRS line.
The change did not touch general-health items that aren’t medicines. Your toothbrush, regular toothpaste, and standard floss still don’t qualify. The rule turns on the product’s classification, not where you buy it. A toothache gel from the pharmacy aisle is eligible; the toothpaste next to it is not.
Cosmetic Dental Work Is Out
Any dental procedure aimed at improving appearance rather than treating a condition is excluded. Teeth whitening is called out by name in Publication 502 as ineligible.1Internal Revenue Service. Publication 502 (2025), Medical and Dental Expenses Cosmetic veneers and elective reshaping fall into the same bucket.
There is an exception for cosmetic work that corrects a deformity caused by a birth defect, an accident, or a disfiguring disease. Reconstructive dental surgery after a car accident or as part of cancer treatment is fully eligible.1Internal Revenue Service. Publication 502 (2025), Medical and Dental Expenses The test is whether the procedure restores function or treats a medical consequence, not whether it happens to improve appearance in the process.
What to Do If You Want to Use FSA Funds for a Toothbrush
Talk to your dentist before you buy. If you have a condition that could support a Letter of Medical Necessity, ask for one that names the specific product and ties it to your diagnosis and treatment plan. Then pay for the brush yourself and file a reimbursement claim with your FSA administrator, attaching the letter and an itemized receipt. If your plan runs a full year and the letter covers ongoing purchases, check whether you’ll need a fresh letter for the next plan year.
If there’s no underlying condition, the brush comes out of your own pocket. Spend the FSA money on the dental expenses that qualify without a letter instead.