Medicare charges and the operational-year coding concept.

The introduction by the Health Care Financing Administration, in 1993, of separate conversion factors for "medical" and "surgical" services to be used in calculating Medicare charges would ordinarily necessitate the use of year-specific software source code. By designing the system to utilize macro-substitution of the year in the names of Current Procedural Terminology for Physicians Code databases, database fields, and system variables, it is possible to calculate Medicare charges without annually rewriting source code. Once such a system is in place, simply by changing the operational year, the correct data and means of computation are automatically available.