The Physiological Systems body system is identified by the character “A” in the 2nd character position and grouped within the Extracorporeal or Systemic Assistance and Performance section of the ICD-10-PCS coding structure. The 2nd character of an ICD-10-PCS code defines the particular body system or general physiological system or anatomical region involved.
A- Physiological Systems
The 3rd character refers to the root operation or the objective of the procedure.
Taking over a portion of a physiological function by extracorporeal means
Completely taking over a physiological function by extracorporeal means
Returning, or attempting to return, a physiological function to its original state by extracorporeal means.