Physiological Systems (6A) ICD-10-PCS
The 6A body system covers Extracorporeal or Systemic Therapies procedures on physiological systems, with 115 ICD-10-PCS codes across 11 root operations, 93 of them billable in fiscal year 2026. 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 · 115 codes
| Chars 1–3 | Root Operation | Codes | Billable |
|---|---|---|---|
| 6A0 | Atmospheric ControlExtracorporeal control of atmospheric pressure and composition | 6 | 4 |
| 6A1 | DecompressionExtracorporeal elimination of undissolved gas from body fluids | 6 | 4 |
| 6A2 | Electromagnetic TherapyExtracorporeal treatment by electromagnetic rays | 10 | 8 |
| 6A3 | HyperthermiaExtracorporeal raising of body temperature | 6 | 4 |
| 6A4 | HypothermiaExtracorporeal lowering of body temperature | 7 | 5 |
| 6A5 | PheresisExtracorporeal separation of blood products | 26 | 24 |
| 6A6 | PhototherapyExtracorporeal treatment by light rays | 10 | 8 |
| 6A7 | Ultrasound TherapyExtracorporeal treatment by ultrasound | 22 | 20 |
| 6A8 | Ultraviolet Light TherapyExtracorporeal treatment by ultraviolet light | 6 | 4 |
| 6A9 | Shock Wave TherapyExtracorporeal treatment by shock waves | 6 | 4 |
| 6AB | PerfusionExtracorporeal treatment by diffusion of therapeutic fluid | 10 | 8 |
The info icon shows the official root operation definition and previews the codes in that range.
About the 6A Body System
The ICD-10-PCS root operation Physiological Systems (Character 6A) involves extracorporeal or systemic therapies designed to alter or manage physiological functions outside the body. This category includes various treatments that regulate body systems through non-invasive means.
Within the Extracorporeal or Systemic Therapies classification, physiological systems codes cover a wide range of procedures such as Atmospheric Control (code 6A0) to manage pressure and gas composition, and Decompression (code 6A1) which removes undissolved gases from body fluids. Other notable examples include therapeutic modalities like Electromagnetic Therapy (6A2), Hyperthermia (6A3), and Hypothermia (6A4) that adjust body temperature externally. Blood product separation by Pheresis (6A5) and various light or wave therapies such as Phototherapy (6A6), Ultrasound Therapy (6A7), and Shock Wave Therapy (6A9) are also included, highlighting the diverse methods of extracorporeal treatment. These codes precisely document systemic interventions aiming to modify physiological conditions without direct surgical manipulation.
Questions About This Page
How many codes are in the 6A body system?
The 6A body system contains 115 ICD-10-PCS codes in FY 2026, organized into 11 root operations. 93 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 2026 ICD-10-PCS order file and code tables, effective October 1, 2025 through September 30, 2026.
