adjusted historical payment basis

In this paragraph, the term “adjusted historical payment basis” means, with respect to a physicians’ service furnished in a fee schedule area, the weighted average prevailing charge applied in the area for the service in 1991 (as determined by the Secretary without regard to physician specialty and as adjusted to reflect payments for services with customary charges below the prevailing charge or other payment limitations imposed by law or regulation) adjusted by the update established under subsection (d)(3) for 1992.