When the principal diagnosis is one of these 18 codes, the CC/MCC codes assigned to this list count as non-CCs (MS-DRG v44 definitions manual, appendix C).
T23.301AT23.302AT23.309AT23.351AT23.352AT23.359AT23.391AT23.392AT23.399AT23.701AT23.702AT23.709AT23.751AT23.752AT23.759AT23.791AT23.792AT23.799A