ICD-10 Code A39.51 – Meningococcal Endocarditis (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code A39.51 – Meningococcal endocarditis
What it is
Meningococcal endocarditis is an infection of the heart valves or inner heart lining caused by Neisseria meningitidis. Use this code when the record specifically documents meningococcal involvement of the endocardium.
Clinical signs
Clinical features may include fever, new or changing heart murmur, embolic findings, or signs of heart failure. Clinical features vary; refer to documentation.
When to use this code
Use A39.51 when the provider diagnoses endocarditis and identifies meningococcal infection as the cause. Apply it for confirmed cases in the current encounter, including situations where blood culture or other documentation supports the organism.
Do not assume this code from meningococcemia alone. If the note only says meningococcal infection without endocarditis, check documentation and code the documented condition instead.
Do not use for
Do not use this code for meningococcal meningitis, meningococcemia without endocarditis, or nonspecific bacterial endocarditis. Check documentation if the organism is not clearly stated.
Coding tip
Assign A39.51 only when the provider links endocarditis to meningococcal infection; otherwise, code the documented cardiac and infectious diagnoses separately.