ICD-10-CM 2027
ICD-10 code for meningococcal infection
From the official ICD-10-CM alphabetic index entry “Infection, infected, infective (opportunistic) › meningococcal”. Page updated September 29, 2026.
About coding meningococcal infection
The ICD-10-CM code for meningococcal infection is A39.9 (Meningococcal infection, unspecified). The official index lists 18 more specific codes, so check the documentation for details such as type, cause, site or severity before settling on A39.9.
Within A39, choose A39.9 (unspecified) only when documentation doesn't support a more specific option: meningococcal meningitis (A39.0), Waterhouse-Friderichsen syndrome (A39.1), acute meningococcemia (A39.2), chronic meningococcemia (A39.3), meningococcemia, unspecified (A39.4), meningococcal heart disease (A39.5) and other meningococcal infections (A39.8).
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 870 (Septicemia or Severe Sepsis with MV >96 Hours, relative weight 6.9408), DRG 871 (Septicemia or Severe Sepsis without MV >96 Hours with MCC, relative weight 1.932) and DRG 872 (Septicemia or Severe Sepsis without MV >96 Hours without MCC, relative weight 1.0066), 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 meningococcal infection codes (official index)
- adrenals A39.1 — Waterhouse-Friderichsen syndrome
- brain A39.81 — Meningococcal encephalitis
- cerebrospinal A39.0 — Meningococcal meningitis
- conjunctiva A39.89 — Other meningococcal infections
- endocardium A39.51 — Meningococcal endocarditis
- heart A39.50 — Meningococcal carditis, unspecified
- endocardium A39.51 — Meningococcal endocarditis
- myocardium A39.52 — Meningococcal myocarditis
- pericardium A39.53 — Meningococcal pericarditis
- joint A39.83 — Meningococcal arthritis
- meninges A39.0 — Meningococcal meningitis
- meningococcemia A39.4 — Meningococcemia, unspecified
- acute A39.2 — Acute meningococcemia
- chronic A39.3 — Chronic meningococcemia
- myocardium A39.52 — Meningococcal myocarditis
- pericardium A39.53 — Meningococcal pericarditis
- retrobulbar neuritis A39.82 — Meningococcal retrobulbar neuritis
- specified site NEC A39.89 — Other meningococcal infections
Common questions about meningococcal infection ICD-10 codes
What is the ICD-10 code for meningococcal infection?
- A39.9 — Meningococcal infection, unspecified. More specific codes apply when the documentation supports them: A39.1, A39.81, A39.0, A39.89 and others below.
What is the ICD-10 code for adrenals meningococcal infection?
- A39.1 — Waterhouse-Friderichsen syndrome.
What is the ICD-10 code for brain meningococcal infection?
- A39.81 — Meningococcal encephalitis.
What is the ICD-10 code for cerebrospinal meningococcal infection?
- A39.0 — Meningococcal meningitis.
What is the ICD-10 code for conjunctiva meningococcal infection?
- A39.89 — Other meningococcal infections.
What is the ICD-10 code for endocardium meningococcal infection?
- A39.51 — Meningococcal endocarditis.
What is the ICD-10 code for heart meningococcal infection?
- A39.50 — Meningococcal carditis, unspecified.
Is A39.9 billable?
- Yes. A39.9 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can A39.9 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict A39.9 as a principal diagnosis.
Is A39.9 a CC or MCC?
- A39.9 is a CC (complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.