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

The ICD-10-CM code for Poisoning by, adverse effect of and underdosing of antiepileptic, sedative- hypnotic and antiparkinsonism drugs is T42 (FY2026). It is a non-billable category code — select a more specific code below for claims.

Classification

Chapter

19: Injury, poisoning and certain other consequences of external causes (S00-T88)

Section

T36-T50: Poisoning by, adverse effects of and underdosing of drugs, medicaments and biological substances (T36-T50)

Category T42

72 codes (54 billable)

FY2026 Status

Stable since FY2024

Official Coding Guidelines

Sequence blood vessel/nerve injury first (fragment)

injury is to the blood vessels or nerves, that injury should be sequenced first.

Do not assign injury codes for iatrogenic injuries; code complication

3) Iatrogenic injuries Injury codes from Chapter 19 should not be assigned for injuries that occur during, or as a result of, a medical intervention. Assign the appropriate complication code(s).

Source: CMS — ICD-10-CM Official Guidelines for Coding and Reporting, FY2026

References

• CMS — ICD-10-CM Official Code Set and Guidelines, FY2026
• CDC/NCHS — ICD-10-CM Files and Browser Tool