1. Practice of billing using numerous CPT codes to identify procedures normally covered by a single code; also known as itemizing, fragmented billing, fragmentation, exploding , or a la carte medicine . 2. Billing under Medicare Part B for nonphysician services to hospital inpatients furnished to the hospital by an outside supplier or another provider. Under the new law, unbundling is prohibited, and all nonphysician services provided in an inpatient setting will be paid as hospital services.