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Free LMN Template

A Letter of Medical Necessity template your doctor can review and sign in under 5 minutes.

What is a Letter of Medical Necessity?

An LMN is a signed letter from your licensed healthcare provider confirming that a specific product is medically necessary to treat a diagnosed condition. Without it, products like smart rings, light therapy lamps, and biofeedback devices cannot be claimed as HSA/FSA expenses — with it, they can be.

A valid LMN must include

Patient's full name and date of birth
Specific diagnosis with ICD-10 code if possible
Exact product name and model
Medical necessity explanation connecting diagnosis to product
Provider name, license number, practice, phone
Provider signature and date

The template

[Date]

To Whom It May Concern:

I am writing on behalf of my patient, [PATIENT FULL NAME], Date of Birth: [MM/DD/YYYY], to confirm that the following product is medically necessary for the treatment of a diagnosed medical condition.

DIAGNOSIS: [Condition name — e.g., "Obstructive Sleep Apnea"] [ICD-10 Code if known — e.g., "G47.33"]

RECOMMENDED PRODUCT: [Full product name and model — e.g., "Oura Ring 4, Titanium"]

MEDICAL NECESSITY: [Patient name] has been diagnosed with [condition]. This device is recommended to [monitor/treat/manage] [specific clinical use — e.g., "nocturnal SpO2 levels and sleep architecture to support management of obstructive sleep apnea"]. General wellness devices that lack clinical monitoring capabilities are not adequate substitutes for this patient's needs.

This recommendation is effective from [start date] and covers a treatment period of [12 months / indefinite for chronic condition].

PROVIDER INFORMATION:
Name: [Full name]
License #: [State license number]
Specialty: [e.g., Sleep Medicine]
Practice: [Practice name]
Address: [Full address]
Phone: [Phone number]

Provider Signature: _________________________ Date: ______________

How to use this template

  1. 1Copy or print the template above.
  2. 2Fill in all bracketed fields — your name, diagnosis, the exact product name and model.
  3. 3Email the completed letter to your doctor's office before your appointment so it's ready to sign when you arrive.
  4. 4At the appointment, your provider reviews, signs, and dates it. Most take under 5 minutes.
  5. 5Purchase your product. Use your HSA/FSA card or pay out of pocket and save the receipt.
  6. 6Log in to your HSA/FSA portal, submit the signed LMN and purchase receipt together under "Submit Claim."

Common conditions that support LMN claims

ConditionCommon products
Obstructive Sleep ApneaSleep monitors, pulse oximeters, smart rings
Atrial Fibrillation (AFib)Heart rate monitors, smart watches, ECG devices
Seasonal Affective DisorderLight therapy lamps (10,000 lux)
Type 2 DiabetesGlucose monitors, activity trackers
Anxiety DisorderBiofeedback devices, weighted blankets
Autism Spectrum DisorderWeighted blankets, sensory tools

LMNs require a real clinical relationship

A valid LMN must come from a licensed provider who has actually evaluated you for the condition. Services that generate LMNs with minimal clinical interaction are a compliance risk. Most major HSA administrators have become skeptical of these services and may deny claims. Use your regular physician or a legitimate telehealth platform.

Not tax or legal advice

This template is provided for informational purposes only. HSA/FSA eligibility for LMN-required products varies by plan administrator. Always confirm with your plan administrator before purchasing. Submitting fraudulent LMNs may result in tax penalties.