|Procedure Class||Major Therapeutic Procedure|
|Medical and Surgical|
|Heart and Great Vessels|
|Replacement||Putting in or on biological or synthetic material that physically takes the place and/or function of all or a portion of a body part|
To determine how a PCS code will affect MS-DRG grouping, you must first look at the patient's primary diagnostic code. The patient will be grouped into the first MDC that lists the primary diagnostic code in the "Assignment of Diagnosis Codes" section.
From there, check the subsections of the MDC. The patient will be mapped into the first subsection for which the treatment performed on the patient meets the listed requirements of that subsection. It most cases, the rules are based based on the PCS codes of the services performed. Sometimes multiple PCS codes are required to qualify.
DRG grouping rules are adjusted each year, so make sure to check the rules for the fiscal year of the patient's discharge date.