Certificate of medical necessity

Generally, a Certificate of Medical Necessity is a piece of paper required by Centers for Medicare and Medicaid Services to substantiate the medical necessity of an item of durable medical equipment furnished to a Medicare beneficiary. It is essentially like a detailed prescription.

A CMN generally contains 6 places where a date can be entered:

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.