Certificate of medical necessity

In the US a certificate of medical necessity is a document required by Centers for Medicare and Medicaid Services to substantiate in detail the medical necessity of an item of durable medical equipment or a service to a Medicare beneficiary.^[1] There are different types of CMN for different requirements, e.g., insulin pumps, home health and private duty nursing services, etc.^[2]

A CMN typically requires several dates to be specified, such as:

1. The "initial date" of the CMN
2. The "revised date" of the CMN
3. The "recertification" date (usually for oxygen)
4. The date the beneficiary signed it
5. The date the supplier signed it and
6. The date the physician signed it.^[2]

• Medical device
• Medical equipment

• Certificates of Medical Necessity/Durable Medical Equipment Information Forms

• Physician's News Digest article on Certificates of Medical Necessity
• Statutory definition of a CMN at the SSA website
• Medicare manual that provides exhaustive information about the practical use of CMNs, particularly section 5.3. This is the official source of information for contractors administering the Medicare system about the use of CMNs.