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3.8. Letter of Medical Necessity

Letter of Medical Necessity

  • The what, who, and when of a 'Letter of Medical Necessity'
  • What is in an effective 'Letter of Medical Necessity'
  • Downloadable 'Letter of Medical Necessity' Overview

Letter of Medical Necessity Overview


The 'Letter of Medical Necessity' is a letter written after your wheelchair assessment to the insurance company paying for your wheelchair that justifies your need for the specific chair requested.  This letter is very descriptive and tells all about what equipment is recommended for you and why. Very often this letter must also include specialists' support and research to back up the medical need for a particular type of wheelchair. 


The clinician or therapist who did your wheelchair evaluation will write the letter of medical necessity, which is addressed to the third party payer or insurance company. Typically, your doctor who wrote your prescription for an assessment co-signs the letter as the 'ordering physician' to support the assessment's findings. 

In addition to the ordering physician, supporting documentation may come from several other specialists who are involved in your care. For example, if you are being treated for a wound or pressure sore, it is good to have documentation from your wound care specialist. This specialist can support your need for pressure relieving features on your wheelchair such as particular seat cushions, power tilt, custom armrests or a standing feature. 


This letter will be written after your wheelchair assessment and submitted to the third party, usually your insurance company, who is paying for the wheelchair. 

The Letter of Medical Necessity's Important Details

What is in a Great and Effective 'Letter of Medical Necessity'?


  • Explains clearly why you need the type of wheelchair you are asking for (power, manual, lightweight, power standing, etc.)


  • Each feature of the wheelchair must be justified as "medically necessary" (insurance companies define "medically necessary", so you want to find out what words they use to define "medical necessity.")
  • Examples of justifications:
    • Tilt feature on a power wheelchair:  "needed to relieve pressure and decrease the risk of pressure sores" 
    • Lightweight manual wheelchair:  "needed to increase endurance due to limited arm strength or arm injury."
    • Cushion to "reduce the risk of pressure sores"

Medically Detailed

  • Describes clearly your diagnosis (spinal cord injury, cerebral palsy, multiple sclerosis, ALS) and how the equipment will help you functionally and medically (breathing, endurance, transfers, independent mobility, etc.). It gets quite medical, but that is what the reviewers are looking for. It is important your therapist and supplier understand why this is important.


  • Includes only information about you that is related to your wheelchair. The letter does not need to talk about your children, your supportive wife or husband - the insurance company might find a reason to deny the wheelchair based on unrelated facts.


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