T31 vs T66
T31 (Burns classified according to extent of body surface involved) compared with T66 (Radiation sickness, unspecified), from the official CMS tabular data. Do not report these codes together: the official tabular list marks them Excludes1.
Can these codes be reported together?
No — do not report together. T66 carries an Excludes1 note covering T31: “burns (T20-T31)”
Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).
Side by side
| T31Burns classified according to extent of body surface involved | T66Radiation sickness, unspecified | |
|---|---|---|
| Billing status | Non-billable header | Non-billable header |
| Classification | S00-T88 — Injury, Poisoning and Certain Other Consequences of External Causes (S00-T88) | S00-T88 — Injury, Poisoning and Certain Other Consequences of External Causes (S00-T88) |
| Definition | Burns classified according to extent of body surface involved is a non-billable ICD-10-CM category code (T31). | Radiation sickness, unspecified is a non-billable ICD-10-CM category code (T66). |
| 7th character | — | The appropriate 7th character is to be added to code T66 |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources