T66
Billable codeRadiation sickness, unspecified
The ICD-10 code for radiation sickness, unspecified is T66.
Clinical notes
Excludes1 (not coded here)
An Excludes1 note is a pure exclusion: the excluded condition and this code should never be reported together, because the two conditions cannot occur at the same time (e.g. a congenital form vs. an acquired form of the same disease).
7th character definitions
These definitions specify what each valid 7th-character value means for codes in this category.
- [object Object]
7th character note
This category requires a 7th character to indicate additional clinical detail (e.g. encounter type: initial, subsequent, sequela). The code is incomplete without it.
- The appropriate 7th character is to be added to code T66
Documentation support
General coding-documentation guidance — not a substitute for payer-specific requirements or professional coding judgment.
- •This code describes an unspecified presentation. If the medical record documents a more specific detail (e.g. laterality, type, or affected site), a more specific sibling code should be used instead — see Related codes below.
- •Confirm the excluded condition(s) listed above are not also present — Excludes1 conditions cannot be coded together with this one.
- •This category requires a 7th character. Documentation should clearly indicate the episode of care (initial encounter, subsequent encounter, or sequela).
- •As a general rule, code to the highest level of specificity supported by the documentation in the medical record.
Related codes in this category
- T67Effects of heat and lightnon-billable header
- T68Hypothermia
- T69Other effects of reduced temperaturenon-billable header
- T70Effects of air pressure and water pressurenon-billable header
- T71Asphyxiationnon-billable header
- T73Effects of other deprivationnon-billable header
- T74Adult and child abuse, neglect and other maltreatment, confirmednon-billable header
- T75Other and unspecified effects of other external causesnon-billable header
- T76Adult and child abuse, neglect and other maltreatment, suspectednon-billable header
- T78Adverse effects, not elsewhere classifiednon-billable header
- T66Radiation sickness, unspecified