A77.40 Ehrlichiosis, unspecified

Billable ICD-10-CM code, FY2026. Acts as a Complication or Comorbidity (CC) as a secondary diagnosis.

Applies from A77.4 Ehrlichiosis

Excludes1 (never code together)

• anaplasmosis [A. phagocytophilum] (A79.82)
• rickettsiosis due to Ehrlichia sennetsu (A79.81)

MS-DRG index

Defines the logic of DRG(s) 867-869 in MDC 18.

Approximate ICD-9-CM (GEMs)

• 082.40 Ehrlichiosis, unspecified

Diagnosis Index entries for A77.40

• Ehrlichiosis
• Fever (inanition) (of unknown origin) (persistent) (with chills) (with rigor) › spotted › Ehrlichiosis

Nearby codes

• A77.0 Spotted fever due to Rickettsia rickettsii
• A77.1 Spotted fever due to Rickettsia conorii
• A77.2 Spotted fever due to Rickettsia siberica
• A77.3 Spotted fever due to Rickettsia australis
• A77.4 Ehrlichiosis
• A77.40 Ehrlichiosis, unspecified (this code)
• A77.41 Ehrlichiosis chaffeensis [E. chaffeensis]
• A77.49 Other ehrlichiosis
• A77.8 Other spotted fevers
• A77.9 Spotted fever, unspecified