T66
T66: Radiation sickness, unspecified
Non-billable headerICD-10-CM
T66 is a non-billable header ICD-10-CM code for radiation sickness, unspecified. It cannot be billed on its own: choose one of the more specific child codes below. This code also requires a 7th character before it is complete.
This code requires a 7th character
The appropriate 7th character is to be added to code T66
- A
- initial encounter
- D
- subsequent encounter
- S
- sequela
Excludes1: never code together
These conditions cannot occur together. Billing both on the same encounter is a denial.
Risk adjustment
No CMS-HCC V28 category: this code does not change a RAF score.
Alphabetic index entries that lead here
- Irradiation effects, adverse
- Effect, adverse›infrared NOS(radiation) (rays)
- Effect, adverse›radiation NOS(diagnostic) (infrared) (natural source) (therapeutic) (ultraviolet) (X-ray)
- Effect, adverse›ultraviolet NOS(radiation) (rays)
- Radiation›effects NOS
- Radiation›sickness NOS
- Sickness›radiation
Code history
Unchanged in every release from FY2024 to FY2027.
Code to one of these instead T66
3 child codes. Green means billable.