ICD-10 Code B25.0 – Cytomegaloviral pneumonitis (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code B25.0 – Cytomegaloviral pneumonitis
What it is
B25.0 identifies pneumonitis caused by cytomegalovirus (CMV), a viral lung infection. Use it when the record specifically documents CMV involvement of the lungs.
Clinical signs
Clinical features vary; refer to documentation. Commonly recorded findings include cough, dyspnea, fever, and imaging evidence of pneumonitis in a patient with confirmed CMV infection.
When to use this code
Use B25.0 when the provider diagnoses CMV pneumonitis, CMV pneumonia, or CMV lung infection affecting the lower respiratory tract. Code it from clear documentation, especially in immunocompromised patients or transplant recipients. If the note only says “CMV infection” without lung involvement, do not assume this code.
Do not use for
Do not use for nonspecific viral pneumonia, other viral pneumonias, or CMV infection without respiratory disease. Check documentation if the lung diagnosis is uncertain.
Coding tip
Look for explicit provider wording linking CMV to pneumonitis or pneumonia before assigning B25.0.