ICD-10 Code B27.82 – Other infectious mononucleosis with meningitis (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code B27.82 – Other infectious mononucleosis with meningitis
What it is
B27.82 identifies infectious mononucleosis caused by an organism other than Epstein-Barr virus, when meningitis is also documented. Use it for a confirmed mononucleosis syndrome with meningeal involvement.
Clinical signs
Findings may include fever, sore throat, lymphadenopathy, fatigue, and signs of meningitis such as headache, neck stiffness, photophobia, or altered mental status. Clinical features vary; refer to documentation.
When to use this code
Use this code when the record clearly links infectious mononucleosis to meningitis and the provider specifies “other” infectious mononucleosis rather than EBV mononucleosis. Apply it for inpatient or outpatient documentation that supports both conditions. Check documentation if the causative agent is unclear.
Do not use for
Do not use B27.82 for EBV infectious mononucleosis without meningitis, or for meningitis from another cause without mononucleosis. If the chart does not support both diagnoses, check documentation.
Coding tip
Code B27.82 only when the provider documents the mononucleosis type and the meningeal complication together.