Can You Buy Food With Your FSA Card? The IRS Test and LMN

You can use your FSA card to buy food only in narrow circumstances: the item has to treat a specific diagnosed medical condition, it cannot be something that meets normal nutritional needs, and a physician has to confirm you need it. Ordinary groceries do not qualify, and even products that do are only reimbursable for the amount they cost above a conventional equivalent.¹ So gluten-free bread for celiac disease, specialty infant formula for a milk protein allergy, and glucose tablets for diabetes can go on the FSA card. A rotisserie chicken, organic berries, or a protein bar you like cannot.

The Three-Part Test the IRS Uses for Food

An FSA can only pay for expenses that count as “medical care” under federal tax law, meaning amounts spent to diagnose, treat, or prevent disease.² For food and beverages, the IRS applies that standard strictly. An item qualifies only when all three of these are true:

It does not satisfy normal nutritional needs. A product you would eat as part of a regular diet, even a healthy one, does not qualify.
It alleviates or treats a diagnosed illness, not general wellness.
A physician has substantiated the need for that specific product.

Miss any one of those and the food is not a medical expense.¹ Organic produce, health-branded snacks, and gluten-free products bought for preference rather than medical necessity are all ineligible, no matter how nutritious they are.

Only the Price Difference Is Reimbursable

When a specialty food does qualify, you cannot claim the full price. You can only claim the amount by which it exceeds the cost of the conventional alternative. If gluten-free bread costs seven dollars and standard bread costs three dollars, the reimbursable medical expense is four dollars, not seven.³ You will need to document the price of the comparable regular product. A screenshot or printout from a grocery store website showing the standard item’s price is usually enough.

Foods and Nutritional Products That Can Qualify

A handful of food-related categories commonly clear the IRS test when backed by the right paperwork.

Specialty infant formula. Formula designed for a specific medical condition, such as a milk protein allergy, is eligible, but only for the cost difference above regular formula. Standard formula used for routine feeding is not eligible.³
Glucose tablets and gels. Products designed to raise blood sugar quickly for people with diabetes are generally eligible as medicinal aids.
Rehydration solutions. Products like Pedialyte are eligible with a Letter of Medical Necessity and a detailed receipt. Electrolyte sports drinks also require a Letter of Medical Necessity.⁴
Gluten-free food. Eligible for a diagnosed condition like celiac disease, again only for the cost difference above the conventional equivalent.³
Meal replacements and medical nutrition. Fortified products prescribed for conditions like malnutrition or metabolic disorders can qualify when they meet the three-part test above.
Vitamins and supplements. Eligible only when a medical practitioner recommends them to treat a specific diagnosed condition. A multivitamin taken for general health does not qualify; iron supplements prescribed for diagnosed iron-deficiency anemia do.¹

The Letter of Medical Necessity

For most specialty food purchases, your FSA administrator will require a Letter of Medical Necessity (LMN) signed by a licensed healthcare provider. The letter connects a specific product to a diagnosed condition and confirms the expense is not for general health or lifestyle reasons.⁵

A complete LMN usually includes:

Your medical diagnosis, such as celiac disease, phenylketonuria, or a severe food allergy.
The specific food item or category your provider is recommending.
A brief explanation of how the product treats the condition.
The duration of treatment. For chronic conditions, providers often list the duration as “lifetime.”⁵
The provider’s signature and date.

An LMN is typically valid for 12 months. If you are making ongoing purchases, like monthly gluten-free groceries, you will need to renew it each year. Get the letter before you start buying, not after. Submitting one retroactively can complicate reimbursement.

How the Card Works at Checkout

Your FSA debit card works at retailers that use the Inventory Information Approval System (IIAS). This flags each item in the store’s system as eligible or ineligible at the register, so the system automatically separates qualifying purchases from regular groceries. Most major pharmacies, large grocery chains, and big-box retailers use IIAS.

When you swipe your FSA card first, it covers only the qualifying items. You pay for the rest with a personal card or cash. The split happens in one transaction. Dedicated online FSA stores sell only pre-vetted eligible products, so the entire purchase goes through on the card without a split.

If your card is declined, whether because the store does not use IIAS, the item is not coded as eligible, or your balance is short, you can pay out of pocket and submit a manual claim. A manual claim needs an itemized receipt showing the date, the store’s name and address, a description of each item, and the amount charged. Credit card statements and canceled checks are not accepted.

Even when the card goes through instantly, keep the itemized receipt. Your plan administrator may ask for proof weeks or months later, and you will need the receipt along with the LMN if one applies.

What Happens If You Buy Something Ineligible

If your FSA card pays for something that turns out not to qualify, your employer’s plan has to follow a correction process the IRS lays out in order:⁶

Your card is deactivated until the improper amount is recovered. You can still get reimbursed for valid expenses by submitting receipts manually.
Your employer asks you to repay the amount directly.
If you do not repay voluntarily, the employer may withhold the amount from your paycheck to the extent allowed by law.
Future reimbursements for legitimate claims are reduced until the balance is recovered. Owe $200 from an improper charge and later submit a valid $250 claim, and you receive $50.
Any remaining balance is treated as a business debt and pursued through the employer’s standard collection practices.

On top of the correction process, any reimbursement that is not properly substantiated gets added to your taxable income, which means you owe income tax and employment tax on that amount. Organized receipts and a current Letter of Medical Necessity are the simplest way to avoid that outcome.

1
Internal Revenue Service. Frequently Asked Questions About Medical Expenses Related to Nutrition, Wellness, and General Health
2
Office of the Law Revision Counsel. 26 U.S. Code 213 – Medical, Dental, Etc., Expenses
3
FSAFEDS. Eligible Health Care FSA (HC FSA) Expenses
4
FSAFEDS. Eligible Health Care FSA (HC FSA) Expenses
5
FSAFEDS. Letter of Medical Necessity
6
Internal Revenue Service. Correction Procedures for Improper Health Flexible Spending Arrangement Payments