ICD-10-CM G21: Secondary parkinsonism

ICD-10-CM Diagnosis Code (2025)

Official Description for G21

Secondary parkinsonism

Coding Notes & Guidelines for G21

Excludes1: Not Coded Here
  • Huntington's disease (G10)
  • neurocognitive disorder with Lewy bodies (G31.83)
  • Shy-Drager syndrome (G90.3)
  • syphilitic Parkinsonism (A52.19)
Excludes1: Not Coded Here

neuroleptic induced parkinsonism (G21.11)

Excludes1: Not Coded Here

malignant neuroleptic syndrome (G21.0)

Code First

(T51-T65) to identify external agent

Use Additional Code

code for adverse effect, if applicable, to identify drug (T43.3X5, T43.4X5, T43.505, T43.595)

Use Additional Code

code for adverse effect, if applicable, to identify drug (T43.3X5, T43.4X5, T43.505, T43.595)

Use Additional Code

code for adverse effect, if applicable, to identify drug (T36-T50 with fifth or sixth character 5)

Inclusion Terms

Other medication-induced parkinsonism

Child Codes (More Specific Codes for G21):

G21.0 - Malignant neuroleptic syndrome G21.1 - Other drug-induced secondary parkinsonism G21.11 - Neuroleptic induced parkinsonism G21.19 - Other drug induced secondary parkinsonism G21.2 - Secondary parkinsonism due to other external agents G21.3 - Postencephalitic parkinsonism G21.4 - Vascular parkinsonism G21.8 - Other secondary parkinsonism G21.9 - Secondary parkinsonism, unspecified

About ICD-10-CM Code G21 (Secondary parkinsonism)

ICD-10-CM code G21 is a billable or specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes. The 2025 edition of ICD-10-CM G21 became effective on October 1, 2024.

This page provides detailed information about G21 - Secondary parkinsonism. It includes common terminology, coding guidelines such as "Includes," "Excludes1," and "Excludes2" notes, and information on required 7th characters. Utilizing this information correctly is essential for accurate medical coding and claims submission for conditions like Secondary parkinsonism.