ICD-10-CM 2027
ICD-10 code for spotted fever
From the official ICD-10-CM alphabetic index entry “Fever (inanition) (of unknown origin) (persistent) (with chills) (with rigor) › spotted”. Page updated September 29, 2026.
About coding spotted fever
The ICD-10-CM code for spotted fever is A77.9 (Spotted fever, unspecified). The official index lists 15 more specific codes, so check the documentation for details such as type, cause, site or severity before settling on A77.9.
Within A77, choose A77.9 (Spotted fever, unspecified) only when documentation doesn't support a more specific option: spotted fever due to Rickettsia rickettsii (A77.0), spotted fever due to Rickettsia conorii (A77.1), spotted fever due to Rickettsia siberica (A77.2), spotted fever due to Rickettsia australis (A77.3), ehrlichiosis (A77.4) and other spotted fevers (A77.8).
As a secondary diagnosis it is a CC (complication or comorbidity), which can move an inpatient stay into the "with CC" MS-DRG of its family, unless the principal diagnosis excludes it.
In MS-DRG v44.0, it is part of the grouping logic for DRG 867 (Other Infectious and Parasitic Diseases Diagnoses with MCC, relative weight 2.1859), DRG 868 (Other Infectious and Parasitic Diseases Diagnoses with CC, relative weight 1.0235) and DRG 869 (Other Infectious and Parasitic Diseases Diagnoses without CC/MCC, relative weight 0.6787), in MDC 18 (Infectious and Parasitic Diseases, Systemic or Unspecified Sites), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
More specific spotted fever codes (official index)
- American A77.0 — Spotted fever due to Rickettsia rickettsii
- Brazilian A77.0 — Spotted fever due to Rickettsia rickettsii
- cerebrospinal meningitis A39.0 — Meningococcal meningitis
- Colombian A77.0 — Spotted fever due to Rickettsia rickettsii
- due to Rickettsia
- africae (African tick bite fever) A77.8 — Other spotted fevers
- australis A77.3 — Spotted fever due to Rickettsia australis
- conorii A77.1 — Spotted fever due to Rickettsia conorii
- parkeri A77.8 — Other spotted fevers
- rickettsii A77.0 — Spotted fever due to Rickettsia rickettsii
- sibirica A77.2 — Spotted fever due to Rickettsia siberica
- specified type NEC A77.8 — Other spotted fevers
- Ehrlichiosis A77.40 — Ehrlichiosis, unspecified
- due to
- E. chaffeensis A77.41 — Ehrlichiosis chaffeensis [E. chaffeensis]
- specified organism NEC A77.49 — Other ehrlichiosis
- Rocky Mountain A77.0 — Spotted fever due to Rickettsia rickettsii
Common questions about spotted fever ICD-10 codes
What is the ICD-10 code for spotted fever?
- A77.9 — Spotted fever, unspecified. More specific codes apply when the documentation supports them: A77.0, A77.0, A39.0, A77.0 and others below.
What is the ICD-10 code for american spotted fever?
- A77.0 — Spotted fever due to Rickettsia rickettsii.
What is the ICD-10 code for brazilian spotted fever?
- A77.0 — Spotted fever due to Rickettsia rickettsii.
What is the ICD-10 code for cerebrospinal meningitis spotted fever?
- A39.0 — Meningococcal meningitis.
What is the ICD-10 code for colombian spotted fever?
- A77.0 — Spotted fever due to Rickettsia rickettsii.
What is the ICD-10 code for ehrlichiosis spotted fever?
- A77.40 — Ehrlichiosis, unspecified.
What is the ICD-10 code for rocky mountain spotted fever?
- A77.0 — Spotted fever due to Rickettsia rickettsii.
Is A77.9 billable?
- Yes. A77.9 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can A77.9 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict A77.9 as a principal diagnosis.
Is A77.9 a CC or MCC?
- A77.9 is a CC (complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.