If you are billing CMS for any Durable Medical Equipment, Prosthetics, Orthotics and Supplies, your documentation must meet Medicare guidelines for CMS to issue payment.
CMS requires documentation to include:
Diagnosis
Type and quantities of items ordered
Frequency of use (or replacement, if applicable)
Duration of the condition
Clinical course (improving or worsening)
Prognosis
Nature and extent of functional limitations
Other therapeutic interventions and results
Experience with related items
The patient medical records may include records from other facilities e.g. hospitals, nursing homes, home health, and other providers to meet medical necessity.
Some DMEPOS items may require a Certificate of Medical Necessity (CMN) or DME Information Form (DIF). It is recommended that a copy be retained in the patient medical record. This form alone is not enough to provide medical necessity.
The documentation does not routinely need to be submitted to DME MAC, however the DME MAC may request this information in selected cases. If the documentation does not support medical necessity when reviewed the provider/supplier of the DME is liable for the cost of the DME, unless a properly executed ABN has been obtained prior to the services rendered.
You can find CMS complete DMEPOS billing guidelines and which items require a CMN/DIF here: Medicare Program Integrity Manual, Chapter 5 (PDF)