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ICD-10-CM 2027 diagnosis code

G21.1Other drug-induced secondary parkinsonism

Not billable — use a more specific code

G21.1 is a header code, so it can't be reported by itself. Choose one of the 2 more specific codes beneath it.

Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About G21.1

G21.1 is the ICD-10-CM diagnosis code for other drug-induced secondary parkinsonism. It belongs to category G21 (secondary parkinsonism), block G20-G26 (extrapyramidal and movement disorders) and chapter 6 (diseases of the nervous system). It is a header code, so it can't be reported by itself; one of its 2 subcodes must be used instead.

Within G21, choose G21.1 (Other drug-induced secondary parkinsonism) only when documentation doesn't support a more specific option: malignant neuroleptic syndrome (G21.0), due to other external agents (G21.2), Postencephalitic parkinsonism (G21.3), vascular parkinsonism (G21.4), other secondary parkinsonism (G21.8) and unspecified (G21.9).

To report this condition, pick the subcode that matches the documentation: G21.11 (parkinsonism) and G21.19 (parkinsonism).

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Specific codes under G21.1

Notes that apply from higher levels

Instructions written at a parent level also apply to G21.1.

› From G21 Secondary parkinsonism
Excludes1
  • Huntington's disease (G10)
  • neurocognitive disorder with Lewy bodies (G31.83)
  • Shy-Drager syndrome (G90.3)
  • syphilitic Parkinsonism (A52.19)

Broader instructions also apply from Chapter 6: Diseases of the nervous system.

Code history

  1. 2016
  2. 2017
  3. 2018
  4. 2019
  5. 2020
  6. 2021
  7. 2022
  8. 2023
  9. 2024
  10. 2025
  11. 2026
  12. 2027
  • FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
  • No changes since FY2016.

Common questions about G21.1

Is G21.1 billable?

No. G21.1 is a header code. Report one of its more specific subcodes instead.