T43.3 — Poisoning by, adverse effect of and underdosing of phenothiazine antipsychotics and neuroleptics
T43.3 is a non-billable header ICD-10-CM code for poisoning by, adverse effect of and underdosing of phenothiazine antipsychotics and neuroleptics. 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 T43
- A
- initial encounter
- D
- subsequent encounter
- S
- sequela
Excludes2 inherited from the categories above T43.3
Also inherited, and the opposite of Excludes1: these conditions are not part of T43.3, but a patient can have both, so you may code both.
Written on T43 — Poisoning by, adverse effect of and underdosing of psychotropic drugs, not elsewhere classified
Other codes that can never be billed with T43.3
These codes carry an Excludes1 note pointing at T43.3. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading T43.3 alone.
- T45.0Poisoning by, adverse effect of and underdosing of antiallergic and antiemetic drugs
Risk adjustment
T43.3 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
T43.3 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 T43.3
1 child code. Green means billable.
Related codes at this level
Codes that share T43. If T43.3 is not quite right, the correct code is usually one of these.
- T43.0Poisoning by, adverse effect of and underdosing of tricyclic and tetracyclic antidepressants
- T43.1Poisoning by, adverse effect of and underdosing of monoamine-oxidase-inhibitor antidepressants
- T43.2Poisoning by, adverse effect of and underdosing of other and unspecified antidepressants
- T43.4Poisoning by, adverse effect of and underdosing of butyrophenone and thiothixene neuroleptics
- T43.5Poisoning by, adverse effect of and underdosing of other and unspecified antipsychotics and neuroleptics
- T43.6Poisoning by, adverse effect of and underdosing of psychostimulants
- T43.8Poisoning by, adverse effect of and underdosing of other psychotropic drugs
- T43.9Poisoning by, adverse effect of and underdosing of unspecified psychotropic drug
Questions about T43.3
- Is T43.3 a billable ICD-10-CM code?
- No. T43.3 is a non-billable header code. Code to a higher level of specificity using one of its child codes.
- Where does T43.3 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).