Understanding Medical Necessity

What "Medically Necessary" Actually Means

Medical necessity is the standard insurers use to decide whether equipment is required to treat, manage, or accommodate a diagnosed condition — as opposed to simply being convenient or preferred. A wheelchair requested because walking is unsafe is medically necessary; the same wheelchair requested purely for convenience on long errands typically isn't, from a payer's perspective.

The Documentation That Proves It

Insurers generally require the same core elements before approving DME as medically necessary, regardless of the specific item requested. Missing any one of these is one of the most common reasons claims get denied.

• A diagnosis that justifies the specific equipment requested
• Documented, measurable functional deficits tied to that diagnosis
• A treatment plan with an expected start date and duration of need
• Evidence that less expensive or alternative options were considered and ruled out
• Clinical notes that clearly connect the equipment to the documented need

The Certificate of Medical Necessity (CMN)

For certain DME categories, Medicare requires a Certificate of Medical Necessity — a specific form your doctor completes stating your diagnosis, prognosis, the reason for the equipment, and how long you're expected to need it. Not every item requires a CMN, but when one is required, an incomplete or missing form is enough to stall a claim entirely.

Why Claims Get Denied

Incomplete clinical notes are the single most common cause of DME claim denials, followed by missed documentation windows, expired prior authorizations, and missing proof of delivery. Most of these gaps are preventable before submission — exactly why a supplier who handles documentation on your behalf can meaningfully cut down on denials.

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