Letter of medical necessity (LMN)

Why the letter exists

Tax-advantaged health accounts can only pay for "medical care" as the tax code defines it. Prescription medicines generally qualify on their own. Other items sit in a gray zone because they can serve either a medical purpose or ordinary wellness.

IRS Publication 502 gives examples. A weight-loss program can count if it treats a specific disease diagnosed by a physician, and vitamins or supplements generally do not count unless a medical practitioner recommends them as treatment for a specific medical condition. A letter documents that link.

What a strong letter includes

• Your name and the date.
• The diagnosis or condition being treated.
• The specific product, program or service recommended.
• How it treats or manages that condition, and the expected duration.
• The clinician's name, credentials and signature.

How it differs from prior authorization

A letter of medical necessity and a prior authorization use similar language, but they serve different audiences. HealthCare.gov defines "medically necessary" as services or supplies needed to diagnose or treat an illness, injury, condition, disease or its symptoms that meet accepted standards of medicine.

A prior authorization is a request to an insurer, usually filed by the prescriber, asking the plan to cover something before you get it. An LMN for an HSA or FSA is typically something you keep or send to your account administrator to support a reimbursement.

Things to know before you ask for one

A letter does not guarantee that an expense qualifies. Your plan administrator decides, and the rules can differ between HSAs, health FSAs and employer-specific plans. Keep the letter with your receipts in case of a later review.

Clinicians write letters only when the facts support them. A letter cannot be issued for a product that is being used purely for general health or appearance.

At HealifyMD

HealifyMD does not bill insurance; HSA or FSA funds may apply depending on your plan. If your administrator asks for documentation, contact support@healifymd.com to ask what records your clinician can provide for your treatment. Prices are confirmed at your eligibility review.

Common situations where one is requested

Administrators most often ask for documentation when a purchase could plausibly be for general health rather than treatment. Examples include structured weight-loss programs for a diagnosed condition, supplements recommended for a documented deficiency, some lab tests ordered for a specific medical reason, and certain equipment. Rules differ between account types and employers, so check with your administrator before assuming an item qualifies.