By Laurie L. Prescott, RN, MSN, CCDS, CDIP, CRC

CDI reviews vary from organization to organization and the regulatory guidance often contains many shades of grey that lead to different interpretations, confusion, and frustration for those wishing to learn. This is particularly true regarding rules governing principal diagnosis sequencing. Sequencing, and identifying the working DRG, is a core function of CDI within the inpatient setting, and it’s one of the most difficult rules to learn.

Principal diagnosis selection so important that the Official Guidelines for Coding and Reporting has an entire section dedicated to it. Section II of the Guidelines is entitled “Selection of Principal Diagnosis.” When I receive questions about sequencing, I prompt the student to go back and read (and in many instances, re-read) these rules.

You can’t stop there and think you’ve learned everything there is to know about principal diagnosis selection, however.