Ear, Nose, Mouth and Throat (D9) ICD-10-PCS
The D9 body system covers Radiation Therapy procedures on ear, nose, mouth and throat, with 680 ICD-10-PCS codes across 4 root operations, 672 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 4 operations · 680 codes
| Chars 1–3 | Root Operation | Codes | Billable |
|---|---|---|---|
| D90 | Beam RadiationA type of radiation therapy that uses a machine to aim high-energy rays at the cancer from outside of the body | 194 | 192 |
| D91 | BrachytherapyA type of radiation therapy in which radioactive material sealed in needles, seeds, wires, or catheters is placed directly into or near a tumor | 338 | 336 |
| D92 | Stereotactic RadiosurgeryA type of external radiation therapy that uses special equipment to position the patient and precisely give a single large dose of radiation to a tumor | 68 | 66 |
| D9Y | Other Radiation | 80 | 78 |
The info icon shows the official root operation definition and previews the codes in that range.
About the D9 Body System
The ICD-10-PCS root operation D9 pertains to Radiation Therapy applied to the Ear, Nose, Mouth, and Throat body system. This operation involves the use of targeted radiation treatments to manage or eradicate disease, primarily cancer, within these areas.
Within this classification, various types of radiation therapy are coded, reflecting different techniques. For example, Beam Radiation (D90) uses external high-energy rays aimed at tumors, while Brachytherapy (D91) involves placing radioactive material directly into or near the tumor to deliver localized treatment. Another specialized procedure, Stereotactic Radiosurgery (D92), precisely delivers a single high dose of radiation using advanced equipment to target the tumor accurately. The code D9Y covers Other Radiation therapies not specifically classified here. These codes enable precise documentation of radiation treatments in the head and neck region, crucial for treatment planning and outcome tracking.
Questions About This Page
How many codes are in the D9 body system?
The D9 body system contains 680 ICD-10-PCS codes in FY 2026, organized into 4 root operations. 672 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.
