Physiological Systems (5A) ICD-10-PCS
The 5A body system covers Extracorporeal or Systemic Assistance and Performance procedures on physiological systems, with 67 ICD-10-PCS codes across 3 root operations, 64 of them billable in fiscal year 2027. Each root operation defines a distinct procedural objective, and the info icons show the official definition with a preview of the codes inside.
Root Operations in This Body System 3 operations · 67 codes
| Chars 1–3 | Root Operation | Codes | Billable |
|---|---|---|---|
| 5A0 | AssistanceTaking over a portion of a physiological function by extracorporeal means | 41 | 40 |
| 5A1 | PerformanceCompletely taking over a physiological function by extracorporeal means | 24 | 23 |
| 5A2 | RestorationReturning, or attempting to return, a physiological function to its original state by extracorporeal means | 2 | 1 |
The info icon shows the official root operation definition and previews the codes in that range.
About the 5A Body System
These codes describe methods outside the body that support, take over, or try to restore heart, circulation, breathing, bile, or urine functions.
The operation distinguishes Assistance, which takes over part of a function, from Performance, which takes it over completely. Restoration returns or attempts to return a function to its original state. The fourth character identifies the function's body system as Cardiac, Circulatory, Respiratory, Biliary, or Urinary.
FY 2027 changes: The FY 2027 ICD-10-PCS update, effective October 1, 2026, added 5 codes in this body system. Tables with changes: 5A0 Assistance and 5A1 Performance.
Questions About This Page
How many codes are in the 5A body system?
The 5A body system contains 67 ICD-10-PCS codes in FY 2027, organized into 3 root operations. 64 of them are billable on inpatient claims.
What is a root operation?
The root operation is the third character of every ICD-10-PCS code and names the objective of the procedure. Drainage takes fluid out, Excision cuts out a portion of a body part, and Resection removes all of one. Picking the right root operation is the central skill of PCS coding, so each one above carries its official CMS definition.
Related References
Source: CMS FY 2027 ICD-10-PCS order file and code tables, effective October 1, 2026 through September 30, 2027.
