CMN
Also written as: CMN — Certificate of Medical Necessity
Abbreviation for Certificate of Medical Necessity; a formal physician-completed form used to justify orthotic and other durable medical equipment prescriptions to payers.
Full Definition
CMN stands for Certificate of Medical Necessity, a key document in the orthotics billing and authorisation workflow. In US Medicare and private insurance claims for orthotics, the CMN establishes medical justification and is often a prerequisite for device approval and reimbursement. Editors processing billing or compliance documents should expand CMN on first use and verify it refers to the structured form rather than any narrative medical justification letter. The CMN is distinct from a prior authorisation request, which is a prospective approval mechanism, and from the HCPCS code, which identifies the device category. Errors in CMN documentation — including incorrect diagnosis codes or missing physician signatures — are a frequent cause of claim denial.
Usage
Usage note: Expand on first use. Distinguish from LMN, which is a narrative letter, not a standardised form.
In Context
- "All custom orthosis claims must be accompanied by a completed CMN bearing the treating physician's original signature." — Insurance submission checklist
- "The editor noted that 'CMN' appeared without expansion in the introduction of the billing manual and flagged it for correction." — Copy-editing feedback