2018 ICD-10-CM Diagnosis Code G21.2

Secondary parkinsonism due to other external agents

Code First
Code First Help
Certain conditions have both an underlying etiology and multiple body system manifestations due to the underlying etiology. For such conditions, ICD-10-CM has a coding convention that requires the underlying condition be sequenced first followed by the manifestation. Wherever such a combination exists there is a "use additional code" note at the etiology code, and a "code first" note at the manifestation code. These instructional notes indicate the proper sequencing order of the codes, etiology followed by manifestation. In most cases the manifestation codes will have in the code title, "in diseases classified elsewhere." Codes with this title are a component of the etiology/manifestation convention. The code title indicates that it is a manifestation code. "In diseases classified elsewhere" codes are never permitted to be used as first listed or principle diagnosis codes. They must be used in conjunction with an underlying condition code and they must be listed following the underlying condition.
  • (T51-T65
    ICD-10-CM Range T51-T65

    Toxic effects of substances chiefly nonmedicinal as to source

    Note
    • When no intent is indicated code to accidental. Undetermined intent is only for use when there is specific documentation in the record that the intent of the toxic effect cannot be determined.
    Type 1 Excludes
    • contact with and (suspected) exposure to toxic substances (Z77.-)
    Use Additional
    • code(s):
    • for all associated manifestations of toxic effect, such as: respiratory conditions due to external agents (J60-J70)
    • personal history of foreign body fully removed (Z87.821)
    • to identify any retained foreign body, if applicable (Z18.-)
    • T51 Toxic effect of alcohol
    • T52 Toxic effect of organic solvents
    • T53 Toxic effect of halogen derivatives of a...
    • T54 Toxic effect of corrosive substances
    • T55 Toxic effect of soaps and detergents
    • T56 Toxic effect of metals
    • T57 Toxic effect of other inorganic substanc...
    • T58 Toxic effect of carbon monoxide
    • T59 Toxic effect of other gases, fumes and v...
    • T60 Toxic effect of pesticides
    • T61 Toxic effect of noxious substances eaten...
    • T62 Toxic effect of other noxious substances...
    • T63 Toxic effect of contact with venomous an...
    • T64 Toxic effect of aflatoxin and other myco...
    • T65 Toxic effect of other and unspecified su...
    ) to identify external agent
The following code(s) above G21.2 contain annotation back-references
Annotation Back-References
In this context, annotation back-references refer to codes that contain:
  • Applicable To annotations, or
  • Code Also annotations, or
  • Code First annotations, or
  • Excludes1 annotations, or
  • Excludes2 annotations, or
  • Includes annotations, or
  • Note annotations, or
  • Use Additional annotations
that may be applicable to G21.2:
  • G00-G99
    2018 ICD-10-CM Range G00-G99

    Diseases of the nervous system

    Type 2 Excludes
    • 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)
    Diseases of the nervous system
  • G21
    ICD-10-CM Diagnosis Code G21

    Secondary parkinsonism

      2016 2017 2018 Non-Billable/Non-Specific Code
    Type 1 Excludes
    • dementia with Parkinsonism (G31.83)
    • Huntington's disease (G10)
    • Shy-Drager syndrome (G90.3)
    • syphilitic Parkinsonism (A52.19)
    Secondary parkinsonism
ICD-10-CM G21.2 is grouped within Diagnostic Related Group(s) (MS-DRG v35.0):

Convert G21.2 to ICD-9-CM

Code History

Diagnosis Index entries containing back-references to G21.2:

ICD-10-CM Codes Adjacent To G21.2
G13.1 Other systemic atrophy primarily affecting central nervous system in neoplastic disease
G13.2 Systemic atrophy primarily affecting the central nervous system in myxedema
G13.8 Systemic atrophy primarily affecting central nervous system in other diseases classified elsewhere
G14 Postpolio syndrome
G20 Parkinson's disease
G21 Secondary parkinsonism
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
G23 Other degenerative diseases of basal ganglia
G23.0 Hallervorden-Spatz disease
G23.1 Progressive supranuclear ophthalmoplegia [Steele-Richardson-Olszewski]
G23.2 Striatonigral degeneration
G23.8 Other specified degenerative diseases of basal ganglia
G23.9 Degenerative disease of basal ganglia, unspecified

Reimbursement claims with a date of service on or after October 1, 2015 require the use of ICD-10-CM codes.