Is T42.6X a billable ICD-10-CM code?

No. T42.6X is a non-billable header code. Code to a higher level of specificity using one of its child codes.

Where does T42.6X sit in the tabular list?

Injury, poisoning and certain other consequences of external causes (S00-T88), in the block Poisoning by, adverse effects of and underdosing of drugs, medicaments and biological substances (T36-T50).

What cannot be coded together with T42.6X?

T42.6X carries Excludes1 notes, which means the conditions they list can never be coded together with it on the same encounter. Some are written on the categories above T42.6X (T42.6) and apply to it just the same.

T42.6X

T42.6X — Poisoning by, adverse effect of and underdosing of other antiepileptic and sedative-hypnotic drugs

Non-billable headerICD-10-CM

T42.6X is a non-billable header ICD-10-CM code for poisoning by, adverse effect of and underdosing of other antiepileptic and sedative-hypnotic drugs. 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 T42

A: initial encounter
D: subsequent encounter
S: sequela

Excludes1 inherited from the categories above T42.6X

These are not written on T42.6X, but they bind it: a note on a category applies to every code beneath it. Billing T42.6X with anything listed here is a denial.

Written on T42.6 — Poisoning by, adverse effect of and underdosing of other antiepileptic and sedative-hypnotic drugs

poisoning by, adverse effect of and underdosing of carbamazepine (T42.1-)

Excludes2 inherited from the categories above T42.6X

Also inherited, and the opposite of Excludes1: these conditions are not part of T42.6X, but a patient can have both, so you may code both.

Written on T42 — Poisoning by, adverse effect of and underdosing of antiepileptic, sedative- hypnotic and antiparkinsonism drugs

drug dependence and related mental and behavioral disorders due to psychoactive substance use (F10.--F19.-)

Risk adjustment

T42.6X 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 history

T42.6X has not changed since FY2024 — no addition, revision or deletion across the three most recent ICD-10-CM releases.

Code to one of these instead T42.6X

6 child codes. Green means billable.

Questions about T42.6X

Is T42.6X a billable ICD-10-CM code?: No. T42.6X is a non-billable header code. Code to a higher level of specificity using one of its child codes.
Where does T42.6X sit in the tabular list?: Injury, poisoning and certain other consequences of external causes (S00-T88), in the block Poisoning by, adverse effects of and underdosing of drugs, medicaments and biological substances (T36-T50).
What cannot be coded together with T42.6X?: T42.6X carries Excludes1 notes, which means the conditions they list can never be coded together with it on the same encounter. Some are written on the categories above T42.6X (T42.6) and apply to it just the same.