2006 proposed fee schedule - American Society of Clinical Oncology

for premium rating purposes. ISO codes classify physicians
not only by specialty, but in many cases also by whether or
not the specialty performs surgical procedures. A given
specialty could thus have two ISO codes, one for use in
rating a member of that specialty who performs surgical
procedures and another for rating a member who does not
perform surgery.
Medicare uses its own system of specialty
classification for payment and data purposes. Therefore, to
calculate the malpractice RVUs, it was necessary to map
Medicare specialties to ISO codes and insurer risk classes.
For some physician specialties, NPP, and other entities (for
example, IDTFs) paid under the PFS, there was not a clear
ISO assignment available. In these instances, we
crosswalked these unassigned specialties to the most
approximate existing ISO codes and risk classes based upon
their relationship to those specialties for which we did
have clear ISO crosswalks. The crosswalks we used to
establish the 2005 malpractice RVUs were displayed in the
November 15, 2004 PFS final rule (69 FR 66268). In most
instances, when an appropriate crosswalk could not be
identified we utilized the average for all physicians
category, which is a weighted average of all specialty
premium data.
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