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A79.81

A79.81Rickettsiosis due to Ehrlichia sennetsu

Billable / specific codeICD-10-CM

A79.81 is a billable, specific ICD-10-CM code for rickettsiosis due to ehrlichia sennetsu. It is valid for submission on a claim.

Inclusion terms

Alternative wordings a physician may use in the chart for this same code.

  • Rickettsiosis due to Neorickettsia sennetsu

Other codes that can never be billed with A79.81

These codes carry an Excludes1 note pointing at A79.81. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading A79.81 alone.

Risk adjustment

A79.81 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.

How A79.81 is indexed

Coders do not find codes by browsing the tabular list — they look them up in the alphabetic index, under the word the physician wrote. These are the index entries that lead here, so you can see which chart wordings map to A79.81.

  • Ehrlichiosisdue toE. sennetsu
  • Rickettsiosisdue toEhrlichia sennetsu
  • Rickettsiosisdue toNeorickettsia sennetsu

Related codes at this level

Codes that share A79.8. If A79.81 is not quite right, the correct code is usually one of these.

Questions about A79.81

Is A79.81 a billable ICD-10-CM code?
Yes. A79.81 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does A79.81 sit in the tabular list?
Certain infectious and parasitic diseases (A00-B99), in the block Rickettsioses (A75-A79).
ICD-10-CMFY2026-Apr· effective April 1, 2026

Loaded directly from the CMS/NCHS ICD-10-CM public-domain release — see data sources and our editorial policy. If this page disagrees with the CMS tabular list, this page is wrong. Reference information for professional coders; not medical or billing advice.