Are lactase pills FSA eligible?

December 17, 2025 •

4 min read

Lactose intolerance affects an estimated 68% of the world's population, making lactase pills a common tool for digestive relief. A frequently asked question for those relying on these products is: are lactase pills FSA eligible? The answer, while not a simple "yes," involves navigating specific IRS rules and documentation requirements.

Quick Summary

Lactase pills are generally not FSA eligible because they are classified as dietary supplements. However, they can be reimbursed if you provide a Letter of Medical Necessity from a healthcare provider, linking the supplement directly to treating your diagnosed lactose intolerance.

Key Points

Not Automatically Eligible: Lactase pills are generally classified as dietary supplements and are not automatically covered by FSAs.
LMN is Required: To be eligible, you must obtain a Letter of Medical Necessity (LMN) from a healthcare provider documenting your lactose intolerance.
LMN Content: The letter must include your diagnosis, the specific treatment (lactase pills), dosage, duration, and the practitioner's signature.
Claim Submission: You must submit both the LMN and an itemized receipt from your purchase to your FSA administrator for reimbursement.
HSA Rules are Similar: The rules for Health Savings Accounts (HSAs) regarding lactase pills and the need for an LMN are similar to those for FSAs.
Retain Documentation: Keep copies of your LMN and all receipts for your records in case of an IRS audit.

Understanding FSA Eligibility Rules

To determine if an expense is eligible for reimbursement with a Flexible Spending Account (FSA), it's essential to understand the criteria set by the IRS. The fundamental rule is that an expense must be primarily for the purpose of medical care, which includes the "diagnosis, cure, mitigation, treatment, or prevention of disease". Items that are merely for general health, like vitamins or dietary supplements, are typically not eligible on their own. This is a crucial distinction that affects how lactase pills are viewed by FSA administrators.

The 2020 Coronavirus Aid, Relief, and Economic Security (CARES) Act expanded the list of FSA-eligible items to include many over-the-counter (OTC) medicines and drugs without a prescription. While this was a major change for many common products like pain relievers and cold medicine, it did not change the rules regarding dietary supplements. Lactase supplements, despite being readily available OTC, are categorized as a supplement and therefore require additional steps to qualify.

The Role of a Letter of Medical Necessity (LMN)

Because lactase pills are considered a dietary supplement, they fall into a "dual-purpose" category for FSA eligibility. This means they are not automatically covered, but can become eligible with proper medical documentation. A Letter of Medical Necessity (LMN) is the key document in this process. An LMN is a written statement from a healthcare provider that confirms a specific item, such as lactase pills, is medically necessary to treat a diagnosed condition, like lactose intolerance.

What must an LMN include?

Your name and information.
The specific diagnosis for which the product is needed (e.g., lactose intolerance).
A description of the recommended treatment, including the specific product (lactase pills), dosage, and frequency.
The duration of the treatment (e.g., "lifetime" for a chronic condition).
The licensed practitioner's name, signature, and the date.

Steps to Get FSA Reimbursement for Lactase Pills

Consult with your doctor: Discuss your lactose intolerance and the use of lactase pills to manage your symptoms. Request an LMN to support your FSA claim.
Obtain a Letter of Medical Necessity (LMN): Your doctor must provide a signed letter on their official letterhead confirming the medical necessity. If your FSA administrator provides a specific form, ensure your doctor completes it.
Purchase the lactase pills: Save the itemized receipt from your purchase. The receipt must clearly show the product name and purchase date.
Submit your claim: File a claim with your FSA administrator, including both the LMN and the itemized receipt. This process can often be done online or via a mobile app, depending on your provider.

Comparison: General OTC Meds vs. Lactase Pills


Feature	Standard OTC Medicine (e.g., Pain Reliever)	Lactase Pills (Dietary Supplement)
Default FSA Eligibility	Generally Eligible (as of the CARES Act)	Not Eligible
Prescription Required	Not Required for most items	Required for the purpose of the LMN
Additional Documentation	Itemized receipt usually sufficient	Letter of Medical Necessity (LMN) is required
Purpose	Treat, mitigate, or prevent disease	Generally for health, but can be for a medical condition

Navigating the Process and Specific FSA Programs

Some third-party platforms are specifically designed to simplify this process for individuals with FSAs and HSAs. For instance, services like TrueMed partner with brands to help customers get the necessary LMN from a licensed provider to qualify for reimbursement. These services can make the process more straightforward than a traditional, manual claim submission.

It's also important to remember that HSA (Health Savings Account) eligibility for lactase pills follows similar rules. Both FSAs and HSAs are governed by the same IRS regulations regarding medical expenses. Always check with your specific plan administrator, as some plans may have additional rules or restrictions, even with an LMN. You should also retain all documentation, including the LMN and itemized receipts, in case of an audit by the IRS.

Conclusion

So, are lactase pills FSA eligible? The simple answer is no, not automatically. However, they can be made eligible with the proper medical documentation. By obtaining a Letter of Medical Necessity from your healthcare provider, you can substantiate your claim that the lactase pills are for a diagnosed medical condition, rather than general health. This allows you to leverage your FSA funds for this expense. While the process requires an extra step, it provides a valuable pathway for those managing lactose intolerance to use their tax-advantaged healthcare funds for their needs. Always consult your FSA provider and medical professional to ensure your documentation is compliant with the latest regulations.

For an example of a letter of medical necessity, you can review the form on the FSAFEDS website.

Frequently Asked Questions

No, because lactase pills are considered dietary supplements and not automatically eligible, your FSA card will likely decline the purchase unless you have an LMN on file and purchase through a certified provider.

No. The CARES Act made many over-the-counter medications eligible without a prescription, but it did not change the rules that require a Letter of Medical Necessity for dietary supplements like lactase pills.

An LMN is a letter from a licensed healthcare provider confirming that a specific item or service, such as lactase pills, is medically necessary for treating your diagnosed condition.

Yes. While Lactaid is typically ineligible as a dietary supplement, you can get reimbursed with a valid Letter of Medical Necessity (LMN) from your doctor.

The eligibility rules for HSAs are the same as FSAs for this purpose. You will need a Letter of Medical Necessity to get reimbursed for lactase pills with your HSA.

You should check with your specific FSA plan administrator, as their interpretation of the rules may vary. However, federal guidelines require an LMN for reimbursement.

You can still request an LMN from your doctor after the purchase, as long as it covers the time frame of your purchase. You can then submit the LMN and your itemized receipt for reimbursement.