MCMCB Pro
T59.5X4

T59.5X4Toxic effect of fluorine gas and hydrogen fluoride, undetermined

Non-billable headerICD-10-CM

T59.5X4 is a non-billable header ICD-10-CM code for toxic effect of fluorine gas and hydrogen fluoride, undetermined. 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 each code from category T59

A
initial encounter
D
subsequent encounter
S
sequela

Risk adjustment

T59.5X4 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.

Code to one of these instead T59.5X4

3 child codes. Green means billable.

Related codes at this level

Codes that share T59.5X. If T59.5X4 is not quite right, the correct code is usually one of these.

Questions about T59.5X4

Is T59.5X4 a billable ICD-10-CM code?
No. T59.5X4 is a non-billable header code. Code to a higher level of specificity using one of its child codes.
Where does T59.5X4 sit in the tabular list?
Injury, poisoning and certain other consequences of external causes (S00-T88), in the block Toxic effects of substances chiefly nonmedicinal as to source (T51-T65).
ICD-10-CMFY2026-Apr· effective April 1, 2026

Loaded directly from the CMS/NCHS ICD-10-CM public-domain release — see data sources and our editorial policy. If this page disagrees with the CMS tabular list, this page is wrong. Reference information for professional coders; not medical or billing advice.