Physiological Systems (XX) ICD-10-PCS
The XX body system covers New Technology procedures on physiological systems, with 28 ICD-10-PCS codes across 3 root operations, 25 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 · 28 codes
| Chars 1–3 | Root Operation | Codes | Billable |
|---|---|---|---|
| XX2 | MonitoringDetermining the level of a physiological or physical function repetitively over a periodof time | 6 | 5 |
| XXA | AssistanceTaking over a portion of a physiological function by extracorporeal means | 3 | 2 |
| XXE | MeasurementDetermining the level of a physiological or physical function at a point in time | 19 | 18 |
The info icon shows the official root operation definition and previews the codes in that range.
About the XX Body System
These New Technology codes cover checks of body functions, including brain electrical activity, blood flow and cardiac conduction. They also cover assistance that takes over part of a function from outside the body.
Measurement checks a function at a point in time. Monitoring checks it repeatedly over time. Assistance takes over part of a function using means outside the body.
FY 2027 changes: The FY 2027 ICD-10-PCS update, effective October 1, 2026, added 1 code and deleted 2 codes in this body system. Table with changes: XXE Measurement.
Questions About This Page
How many codes are in the XX body system?
The XX body system contains 28 ICD-10-PCS codes in FY 2027, organized into 3 root operations. 25 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.
