Excludes1 pair
T31- vs T66-
T31 and T66 are not coded together. ICD-10-CM declares them mutually exclusive with an Excludes1 note — the two conditions are not expected to occur together, so exactly one of them is normally correct for a given encounter. The Official Guidelines carve out one exception: if the two conditions are clearly unrelated to each other, both may be reported.
The official note, declared on T66
burns (T20-T31)
T31
Burns classified according to extent of body surface involved
Not billable
- Chapter 19
- Injury, poisoning and certain other consequences of external causes
- Section
- T30-T32
T66
Radiation sickness, unspecified
Not billable
- Chapter 19
- Injury, poisoning and certain other consequences of external causes
- Section
- T66-T78
Indexed under
- 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
Excludes1 is not always absolute: where two conditions covered by the note are genuinely unrelated, CMS guidance permits reporting both. Document the reasoning rather than assuming it. More on Excludes1 vs Excludes2 · FY2027