A42.9 Actinomycosis, unspecified

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

Applies from A42 Actinomycosis

Excludes1 (never code together)

• actinomycetoma (B47.1)

MS-DRG index

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

Approximate ICD-9-CM (GEMs)

• 039.9 Actinomycotic infection of unspecified site (approximate)

Diagnosis Index entries for A42.9

• Actinomycosis, actinomycotic
• Infection, infected, infective (opportunistic) › Actinomyces (israelii)

Nearby codes

• A42.7 Actinomycotic sepsis
• A42.8 Other forms of actinomycosis
• A42.81 Actinomycotic meningitis
• A42.82 Actinomycotic encephalitis
• A42.89 Other forms of actinomycosis
• A42.9 Actinomycosis, unspecified (this code)