Excisional Debridement - Coding for the Deepest Layer

Procedure code assignment for excisional debridement has always been a focus area in coding audits.  The biggest concern is determining whether or not the method of debridement is truly excisional in nature, and if the documentation truly supports an excisional debridement. It is also important to note that direction in Coding Clinic states the excisional debridement is the definitive procedure when both excisional and nonexcisional debridement are carried out at the same site, so only the code for excision debridement is assigned. 

Another concern is choosing the proper ICD-10-PCS body system (Skin, Subcutaneous Tissue and Fascia, Muscle, Bone etc.) from which to assign an excisional debridement code.  Errors in choosing the proper body system value can lead to incorrect procedure codes and thus incorrect DRG assignment and reimbursement.

What do the Official Guidelines for Coding and Reporting state?

ICD-10-PCS Guideline B3.5 – Overlapping body layers states:  “If the root operations Excision, Repair or Inspection are performed on overlapping layers of the musculoskeletal system, the body part specifying the deepest layer is coded. Example: Excisional debridement that includes skin and subcutaneous tissue and muscle is coded to the muscle body part.”

This guideline states that for when coding for excisional debridement, the body system value of an ICD-10-PCS code should correspond to the deepest layer of tissue debrided. In this case, it is muscle.  It is understood that excision of the layers of tissue above the muscle are included in this single code for excision of muscle.  

Another challenge for coders is to choose not only the correct body system value, but also the correct body part value. For example, if excisional debridement is performed on a sacral ulcer with excision down to and including muscle, what body part value should the coder choose?  The answer is “Hip muscle.” If the documentation specifies whether the right or left side of the ulcer was debrided, only a single code, 0KBN/P0ZZ, Excision of Right/Left Hip Muscle, Open Approach is correct. If laterality is not specified, two codes, one with a body part value of right hip muscle and one with a body part value of left hip muscle are assigned.    

A second example includes excisional debridement of skin and subcutaneous tissue of the right breast. In this case, subcutaneous tissue is the deepest layer debrided, but there is no body part value for subcutaneous tissue of the breast. Coders may be tempted to use the body part, Subcutaneous Tissue and Fascia, Chest, but AHA Coding Clinic clarifies that the correct body system value is Skin and Breast and the correct part value for this procedure is Right Breast.  

When questions arise about which body part value to assign, coders should consult the ICD-10-PCS Body Part Key and the official advice in AHA Coding Clinic for direction.  

For more examples, please refer to the AHA Coding Clinics listed in the references,  

References 

AHA Coding Clinic, Second Quarter 2023, Page 30 

AHA Coding Clinic, Second Quarter 2020: Page 26 

AHA Coding Clinic, Third Quarter 2018: Page 17 

AHA Coding Clinic, First Quarter 2018: Page 14 

AHA Coding Clinic, Third Quarter 2016: Page 20 

AHA Coding Clinic, Third Quarter 2015; Pages 3-8 

AHA Coding Clinic, First Quarter 2013 Pages: 15-17 

ICD-10-PCS Official Guidelines for Coding and Reporting 2016