ICD-9-CM diagnosis code (retired)
966.4 — Poisoning by anti-Parkinsonism drugs
About ICD-9-CM 966.4
966.4 is an ICD-9-CM diagnosis code for poisoning by anti-Parkinsonism drugs. ICD-9-CM was retired for U.S. claims on October 1, 2015, when ICD-10-CM took over.
The CMS General Equivalence Mappings translate it to 4 ICD-10-CM codes, such as T42.8X1A (Poisoning by antiparkinsonism drugs and other central muscle-tone depressants, accidental (unintentional), initial encounter), T42.8X2A (Poisoning by antiparkinsonism drugs and other central muscle-tone depressants, intentional self-harm, initial encounter) and T42.8X3A (Poisoning by antiparkinsonism drugs and other central muscle-tone depressants, assault, initial encounter). All of these are approximate matches, so review the record to pick the right one.
ICD-10-CM equivalents
- T42.8X1APoisoning by antiparkinsonism drugs and other central muscle-tone depressants, accidental (unintentional), initial encounterapproximate
- T42.8X2APoisoning by antiparkinsonism drugs and other central muscle-tone depressants, intentional self-harm, initial encounterapproximate
- T42.8X3APoisoning by antiparkinsonism drugs and other central muscle-tone depressants, assault, initial encounterapproximate
- T42.8X4APoisoning by antiparkinsonism drugs and other central muscle-tone depressants, undetermined, initial encounterapproximate
Common questions about 966.4
GEMs are a translation aid, not a substitute for coding from the record. The 2027 ICD-10 code set has changed since the last GEMs release in 2018. Page updated September 29, 2026.