837P

The 837P is the professional claim as a data file. Where a paper CMS-1500 has numbered boxes, the 837P has loops and segments: billing provider, subscriber, patient, payer, claim header and then one service line after another. Each service line carries the procedure code and modifiers, units, charge, dates of service, place of service and the diagnosis pointers that tie the line back to the diagnosis codes in the claim header. Rendering, referring and supervising providers are identified by NPI, the billing provider by NPI and tax ID, and the payer by its electronic payer ID. CMS requires professional providers billing Medicare electronically to follow the ASC X12 837 Professional implementation guide, version 005010X222A1, and the same transaction is what clearinghouses send on to other payers.

The 837P matters because almost every non-facility claim travels in this format. Physician offices, behavioral health practices, therapists, home health agencies billing professional services, DME suppliers, labs, ambulance and non-emergency medical transportation providers all send 837P files, and payers’ front-end edits, acknowledgments and rejections are written in terms of its loops and segments. When a clearinghouse rejection says a value in a particular loop is invalid, it is pointing at this structure.

The mistake is thinking of the 837P as a form your software fills in. What the payer receives is whatever the practice management system mapped from its own fields, and a missing taxonomy code, a referring provider in the wrong loop or an authorization number typed into a claim note rather than its proper segment will reject or deny even though the screen looked complete. Learn how your system maps to the 837P, and read the 999 and 277CA acknowledgments that come back.