The customary and prevailing fee amounts are subject to a variety of constraints and inventives such as:
For some services, the Medicare allowed charge was not equal to the billed amount, customary fee, or prevailing fee.
For certain physician services, carriers were unable to establish a customary or prevailing fee.
Lower prevailing fees for non-participating (NON-PAR) physicians.
The lower prevailing fees for NON-PAR physicians (96 percent in 1987, 95.
5 percent of the prevailing fees for PARs, down from 96 percent in FSY 1987.