Definition
Medical billing translates coded services into claims and follows them through to payment. Billers build claims on the CMS-1500 or UB-04, or the electronic 837P and 837I. They submit claims, post remittances, work denials, and bill patients for their share.
Why it matters
Billing is where coding, enrollment, and registration data all have to agree. A mismatch in provider NPI, payer ID, or patient details causes a rejection or denial. Slow follow-up pushes claims past timely filing limits, and that revenue becomes a write-off.
Example
A biller submits an 837P for an office visit and receives a 277CA rejection for an invalid member ID. She corrects the ID and resubmits the claim the same day.