ICD-10 · PDGM grouping
A83 Mosquito-borne viral encephalitis
All 9 codes in the A83 family, with the PDGM clinical group, comorbidity subgroup and primary-position rule CMS assigns, read from the CMS grouper crosswalk v07.2.26 and the CDC FY2027 code file.
Codes in family
9
Can lead a claim
9
Cannot lead a claim
0
What CMS assigns to A83
All 9 codes group to Neuro Rehabilitation. None of the 9 is assigned a comorbidity subgroup. Every code can lead a claim.
Every code in A83
Descriptions are CDC’s FY2027 wording; where CMS’s grouper abbreviates one, its form is shown beneath.
| Code | Description | Primary position | Clinical group | Comorbidity subgroup |
|---|---|---|---|---|
| A83.0 | Japanese encephalitis | Can lead a claim | B | None |
| A83.1 | Western equine encephalitis | Can lead a claim | B | None |
| A83.2 | Eastern equine encephalitis | Can lead a claim | B | None |
| A83.3 | St Louis encephalitis | Can lead a claim | B | None |
| A83.4 | Australian encephalitis | Can lead a claim | B | None |
| A83.5 | California encephalitis | Can lead a claim | B | None |
| A83.6 | Rocio virus disease | Can lead a claim | B | None |
| A83.8 | Other mosquito-borne viral encephalitis | Can lead a claim | B | None |
| A83.9 | Mosquito-borne viral encephalitis, unspecified | Can lead a claim | B | None |
Sources: CMS HH PPS Grouper Software v07.2.26, effective 2026-10-01, for the clinical group, comorbidity subgroup, code-first conventions and primary-position flags; CDC NCHS ICD-10-CM FY2027 code descriptions for the family title and code wording. This is the crosswalk Medicare runs a claim through. Grouping also depends on admission source, timing, the OASIS functional items and the rest of the diagnosis list.
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