Physiological Systems (6A) ICD-10-PCS
The 6A body system covers Extracorporeal or Systemic Therapies procedures on physiological systems, with 58 ICD-10-PCS codes across 11 root operations, 47 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 11 operations · 58 codes
| Chars 1–3 | Root Operation | Codes | Billable |
|---|---|---|---|
| 6A0 | Atmospheric ControlExtracorporeal control of atmospheric pressure and composition | 3 | 2 |
| 6A1 | DecompressionExtracorporeal elimination of undissolved gas from body fluids | 3 | 2 |
| 6A2 | Electromagnetic TherapyExtracorporeal treatment by electromagnetic rays | 5 | 4 |
| 6A3 | HyperthermiaExtracorporeal raising of body temperature | 3 | 2 |
| 6A4 | HypothermiaExtracorporeal lowering of body temperature | 4 | 3 |
| 6A5 | PheresisExtracorporeal separation of blood products | 13 | 12 |
| 6A6 | PhototherapyExtracorporeal treatment by light rays | 5 | 4 |
| 6A7 | Ultrasound TherapyExtracorporeal treatment by ultrasound | 11 | 10 |
| 6A8 | Ultraviolet Light TherapyExtracorporeal treatment by ultraviolet light | 3 | 2 |
| 6A9 | Shock Wave TherapyExtracorporeal treatment by shock waves | 3 | 2 |
| 6AB | PerfusionExtracorporeal treatment by diffusion of therapeutic fluid | 5 | 4 |
The info icon shows the official root operation definition and previews the codes in that range.
About the 6A Body System
These codes cover therapies performed outside the body that control atmospheric conditions, act on body fluids, change body temperature, or use rays, ultrasound or shock waves.
Atmospheric control changes pressure or air composition. Decompression removes undissolved gas from body fluids, while pheresis separates blood products. Hyperthermia raises body temperature; hypothermia lowers it. Other tables cover treatment with electromagnetic rays, light, ultraviolet light, ultrasound or shock waves, and perfusion through the diffusion of therapeutic fluid. The fourth character can name a body system, such as Circulatory or Skin, or take the value None.
Questions About This Page
How many codes are in the 6A body system?
The 6A body system contains 58 ICD-10-PCS codes in FY 2027, organized into 11 root operations. 47 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.
