ICD-10 code for secondary parkinsonism

The ICD-10-CM code for secondary parkinsonism is G21.9 (Secondary parkinsonism, unspecified). The official index lists 7 more specific codes, so check the documentation for details such as type, cause, site or severity before settling on G21.9.

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

As a secondary diagnosis it is a CC (complication or comorbidity), which can move an inpatient stay into the "with CC" MS-DRG of its family, unless the principal diagnosis excludes it.

In MS-DRG v44.0, it is part of the grouping logic for DRG 056 (Degenerative Nervous System Disorders with MCC, relative weight 2.2655) and DRG 057 (Degenerative Nervous System Disorders without MCC, relative weight 1.2838), in MDC 01 (Diseases and Disorders of the Nervous System), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.