ICD-10 Code B25 – Cytomegaloviral disease (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code B25 – Cytomegaloviral disease
What it is
B25 identifies cytomegaloviral disease, an illness caused by cytomegalovirus infection. Use it when the record documents active CMV disease rather than simple exposure or carrier status.
Clinical signs
Clinical features vary; refer to documentation. CMV disease may include organ-specific infection, systemic illness, or findings consistent with active viral disease in an immunocompromised or other affected patient.
When to use this code
Use B25 when the provider documents cytomegaloviral disease, CMV infection with illness, or CMV involvement of a specific organ system. Apply it only when the note supports active disease, not just past infection or positive serology.
If the record is unclear about whether CMV is causing current illness, check documentation before coding. You may need a more specific subcategory if the site or manifestation is stated.
Do not use for
Do not use B25 for CMV exposure, history of CMV, or asymptomatic laboratory evidence alone. Do not code it when documentation does not support active disease; check documentation.
Coding tip
Look for provider wording such as “CMV disease” or “CMV infection” with current illness, and code the most specific documented manifestation when available.