G21.3
G21.3: Postencephalitic parkinsonism
Billable / specific codeICD-10-CM
G21.3 is a billable, specific ICD-10-CM code for postencephalitic parkinsonism. It is valid for submission on a claim.
Check G21.3 with the rest of the claim: free scrubberOther codes that can never be billed with G21.3
Their own Excludes1 notes name this code, so the conflict is not listed above.
- G20.CParkinsonism, unspecified
Risk adjustment
G21.3 risk-adjusts. Under the CMS-HCC V28 model it maps to this category:
- HCC 199 Parkinson and Other Degenerative Disease of Basal Ganglia0.615 RAF
Coefficient shown for the Community Non-dual Aged segment. A higher HCC in the same hierarchy will suppress this one, so capturing it does not always add score. Look up the whole chart to see which of its HCCs the hierarchy would zero.
Medicare coverage
G21.3 is named in 12 Medicare coverage policies: 12 listing it as supporting medical necessity. Which one applies depends on your Medicare contractor.
- A54111Billing and Coding: Speech Language Pathology (SLP) Services: Communication Disorders
- A56612Billing and Coding: CT of the Head
- A56619Billing and Coding: Nerve Conduction Studies and Electromyography
- A56621Billing and Coding: Swallowing Studies for Dysphagia
Alphabetic index entries that lead here
- Parkinsonism›postencephalitic
- Parkinsonism›secondary›due to›encephalitis
Code history
Unchanged in every release from FY2024 to FY2027.