The way many coders have been assigning their DRG principal procedure codes could be wrong, according to the fourth quarter 2012 Coding Clinic.

Sweeping changes and clarification on coding rules related to principal procedure assignment were explained in the latest Coding Clinic, and coders should be making the adjustment, according to Richard Averill, senior vice president of clinical and economic research at 3M Health Information Systems.

In this audio interview with Journal of AHIMA Editor-in-Chief Chris Dimick, Averill clarifies the rules for designating the principal procedure, which he feels had been “ambiguously defined” and “open to interpretation” prior to the release of the Coding Clinic in October. Averill, a principal researcher for the Centers for Medicare and Medicaid Services who helped create the DRG system, says the move to value-based purchasing is the reason for the change in coding rules.

This interview, recorded during the 84th AHIMA Convention and Exhibit in October, is the first of a four part series that will appear on this site each week in December.