Certificate of Medical Necessity
Also written as: CMN — Certificate of Medical Necessity
A standardized document, signed by a licensed physician, that certifies a patient's medical need for a prosthetic or durable medical equipment item as a prerequisite for insurance reimbursement.
Full Definition
A Certificate of Medical Necessity (CMN) is a form required by Medicare and many private insurers to authorize and reimburse prosthetic devices and other DMEPOS items. It must be completed and signed by the treating physician and typically specifies diagnosis codes, functional assessment results, and the equipment requested. Editors must distinguish the CMN from the Letter of Medical Necessity (LMN), which is a narrative document rather than a structured form, and from a prior-authorization request. Correct abbreviation is CMN (not CMS, which refers to the regulatory agency).
Usage
Usage note: Expand to 'Certificate of Medical Necessity (CMN)' on first use. Do not confuse with 'Letter of Medical Necessity (LMN),' which is a different document type.
In Context
- "The billing specialist returned the claim because the Certificate of Medical Necessity had not been countersigned by the ordering physician." — Insurance billing correspondence
- "A CMN is a structured form, whereas a Letter of Medical Necessity is a narrative; the editor should confirm which document is referenced in the text." — Editorial style note