Is T65 a billable ICD-10-CM code?

No. T65 is a non-billable header code. Code to a higher level of specificity using one of its child codes.

Where does T65 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).

T65

T65 — Toxic effect of other and unspecified substances

Non-billable headerICD-10-CM

T65 is a non-billable header ICD-10-CM code for toxic effect of other and unspecified substances. 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 T65

A: initial encounter
D: subsequent encounter
S: sequela

Other codes that can never be billed with T65

These codes carry an Excludes1 note pointing at T65. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading T65 alone.

T52.1Toxic effects of benzene
T60.4Toxic effect of rodenticides
T61Toxic effect of noxious substances eaten as seafood
T62Toxic effect of other noxious substances eaten as food

Risk adjustment

T65 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 T65

9 child codes. Green means billable.

Questions about T65

Is T65 a billable ICD-10-CM code?: No. T65 is a non-billable header code. Code to a higher level of specificity using one of its child codes.
Where does T65 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).