Letter of Medical Necessity for Red Light Therapy (Free Template)

A Letter of Medical Necessity (LMN) is a short note from a licensed healthcare provider stating that a product is needed to treat or manage a specific medical condition. Many FSA/HSA administrators require one before reimbursing wellness devices like red light therapy.

Who can write one?

A licensed provider involved in your care — typically a physician (MD/DO), nurse practitioner (NP), or physician assistant (PA). A chiropractor, dermatologist, or physical therapist may also qualify depending on your plan.

What an LMN should include

• Your name and the date.
• Your diagnosed condition (e.g., chronic low-back pain, osteoarthritis).
• The recommended product or treatment (e.g., red light therapy device, 660nm/850nm).
• Medical justification — why it is needed and how it helps manage the condition.
• Duration of recommended use (e.g., 12 months).
• Provider’s name, credentials, signature, and contact info.

Steps to get one

1. Talk to your provider about using red light therapy for your condition.
2. Ask them to write an LMN including the elements above (bring the template below).
3. Submit the LMN with your receipt to your FSA/HSA administrator.
4. Keep a copy; LMNs often need annual renewal.

Free LMN template

Copy and paste this for your provider:

[Provider Letterhead]

Date: ____________________

To Whom It May Concern (FSA/HSA Plan Administrator):

Patient Name: ____________________
Date of Birth: ____________________

I am the treating provider for the above patient. Based on my clinical
evaluation, the patient has been diagnosed with: ____________________
(ICD-10 code, if available: __________).

As part of the patient's treatment plan, I recommend the use of a
red light / near-infrared light therapy device (660nm + 850nm) to help
manage this condition. This device is medically necessary to [reduce pain /
support recovery / manage the diagnosed condition], and is recommended for
use for a period of ____ months.

Please consider this expense eligible for reimbursement under the patient's
FSA/HSA plan.

Provider Name: ____________________
Credentials: ____________________
NPI #: ____________________
Signature: ____________________
Contact: ____________________

See also: Is Red Light Therapy FSA/HSA Eligible?

Educational only; not medical, tax, or legal advice. Your provider determines medical necessity, and your plan administrator determines reimbursement. Requirements vary by plan.