A75 vs A79.81
A75 (Typhus fever) compared with A79.81 (Rickettsiosis due to Ehrlichia sennetsu), from the official CMS tabular data. Do not report these codes together: the official tabular list marks them Excludes1.
Can these codes be reported together?
No — do not report together. A75 carries an Excludes1 note covering A79.81: “rickettsiosis due to Ehrlichia sennetsu (A79.81)”
Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).
Side by side
| A75Typhus fever | A79.81Rickettsiosis due to Ehrlichia sennetsu | |
|---|---|---|
| Billing status | Non-billable header | Billable |
| Classification | A00-B99 — Certain Infectious and Parasitic Diseases (A00-B99) | A00-B99 — Certain Infectious and Parasitic Diseases (A00-B99) |
| Definition | Typhus fever is a non-billable ICD-10-CM category code (A75). | Rickettsiosis due to Ehrlichia sennetsu is a billable ICD-10-CM diagnosis code (A79.81). |
| Includes | — | Rickettsiosis due to Neorickettsia sennetsu |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources