G21Non-billableSave
G21 - Secondary parkinsonism
ICD-10-CM Chapter 6: Diseases of the nervous system · G20-G26 Extrapyramidal and movement disorders (G20-G26) · Top-level category · FY2027
Coding Guidance
G21 is a non-billable heading. Report one of the 7 more specific codes below.
Includes, Excludes and Coding Notes
Excludes 1 — Not Coded HereFrom G21
Mutually exclusive: these conditions are never reported together with this code.
- Huntington's disease (G10)
- neurocognitive disorder with Lewy bodies (G31.83)
- Shy-Drager syndrome (G90.3)
- syphilitic Parkinsonism (A52.19)
Excludes 2 — Not Included HereFrom Chapter G00-G99
Not part of this code; report both codes when the patient has both conditions.
- certain conditions originating in the perinatal period (P04-P96)
- certain infectious and parasitic diseases (A00-B99)
- complications of pregnancy, childbirth and the puerperium (O00-O9A)
- congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
- endocrine, nutritional and metabolic diseases (E00-E88)
- injury, poisoning and certain other consequences of external causes (S00-T88)
- neoplasms (C00-D49)
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
More Specific Codes (7)
G21.0Malignant neuroleptic syndromeBillable→G21.1Other drug-induced secondary parkinsonismCategory→G21.2Secondary parkinsonism due to other external agentsBillable→G21.3Postencephalitic parkinsonismBillable→G21.4Vascular parkinsonismBillable→G21.8Other secondary parkinsonismBillable→G21.9Secondary parkinsonism, unspecifiedBillable→
Related condition guides
Documentation requirements, coding pitfalls and FAQs for conditions coded with G21.
Chapter Information
Related ICD-10 Codes
More specific codes for G21
Other categories in this chapter
Codes at the same level as G21
- Bacterial meningitis, not elsewhere classifiedG00
- Meningitis in bacterial diseases classified elsewhereG01
- Meningitis in other infectious and parasitic diseases classified elsewhereG02
- Meningitis due to other and unspecified causesG03
- Encephalitis, myelitis and encephalomyelitisG04
- Encephalitis, myelitis and encephalomyelitis in diseases classified elsewhereG05
- Intracranial and intraspinal abscess and granulomaG06
- Intracranial and intraspinal abscess and granuloma in diseases classified elsewhereG07
- Intracranial and intraspinal phlebitis and thrombophlebitisG08
- Sequelae of inflammatory diseases of central nervous systemG09
- Huntington's diseaseG10
- Hereditary ataxiaG11
- Spinal muscular atrophy and related syndromesG12
- Systemic atrophies primarily affecting central nervous system in diseases classified elsewhereG13
- Postpolio syndromeG14
- Parkinson's diseaseG20
- Other degenerative diseases of basal gangliaG23
- DystoniaG24
- Other extrapyramidal and movement disordersG25
- Extrapyramidal and movement disorders in diseases classified elsewhereG26
- Alzheimer's diseaseG30
- Other degenerative diseases of nervous system, not elsewhere classifiedG31
- Other degenerative disorders of nervous system in diseases classified elsewhereG32
- Multiple sclerosisG35
- Other acute disseminated demyelinationG36
- Other demyelinating diseases of central nervous systemG37
- Epilepsy and recurrent seizuresG40
- MigraineG43
- Other headache syndromesG44
- Transient cerebral ischemic attacks and related syndromesG45
- Vascular syndromes of brain in cerebrovascular diseasesG46
- Sleep disordersG47
- Disorders of trigeminal nerveG50
- Facial nerve disordersG51
- Disorders of other cranial nervesG52
- Cranial nerve disorders in diseases classified elsewhereG53
- Nerve root and plexus disordersG54
- Nerve root and plexus compressions in diseases classified elsewhereG55
- Mononeuropathies of upper limbG56
- Mononeuropathies of lower limbG57
27 more in this chapter.