Durable medical equipment claims run into documentation trouble more than most other billing types, since payers require detailed proof of medical necessity tied specifically to the equipment prescribed, along with physician orders and sometimes face-to-face documentation requirements. Missing paperwork is one of the most common reasons DME claims get denied outright. DME billing services need every piece of required documentation verified before submission, not after a denial forces a resubmission, since DME claims tend to take considerably longer to resolve once they've been kicked back for missing information the first time around.