ICD-10 · PDGM grouping
A77 Spotted fever [tick-borne rickettsioses]
All 9 codes in the A77 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 A77
All 9 codes group to MMTA - Infectious Disease, Neoplasms, and Blood-Forming Diseases. None of the 9 is assigned a comorbidity subgroup. Every code can lead a claim.
Every code in A77
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 |
|---|---|---|---|---|
| A77.0 | Spotted fever due to Rickettsia rickettsii | Can lead a claim | K | None |
| A77.1 | Spotted fever due to Rickettsia conorii | Can lead a claim | K | None |
| A77.2 | Spotted fever due to Rickettsia siberica | Can lead a claim | K | None |
| A77.3 | Spotted fever due to Rickettsia australis | Can lead a claim | K | None |
| A77.4 Ehrlichiosis | ||||
| A77.40 | Ehrlichiosis, unspecified | Can lead a claim | K | None |
| A77.41 | Ehrlichiosis chaffeensis [E. chaffeensis] | Can lead a claim | K | None |
| A77.49 | Other ehrlichiosis | Can lead a claim | K | None |
| A77.8 | Other spotted fevers | Can lead a claim | K | None |
| A77.9 | Spotted fever, unspecified | Can lead a claim | K | 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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