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.