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. There are different types of CMN for different requirements, e.g., insulin pumps, home health and private duty nursing services, etc.

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.