ICD-10 Code B01.9 – Varicella without complication (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code B01.9 – Varicella without complication
What it is
B01.9 identifies varicella, or chickenpox, when the infection is present but no complication is documented. Use it for uncomplicated cases caused by varicella-zoster virus.
Clinical signs
Typical findings include a generalized itchy vesicular rash that appears in crops, often with fever or malaise. If the record does not show complications, this code may apply.
When to use this code
Use B01.9 when the provider documents chickenpox or varicella and does not describe pneumonia, encephalitis, or other complications. It also fits routine outpatient or inpatient encounters for an uncomplicated active infection. If the note is unclear, check documentation.
Do not use for
Do not use this code for varicella with a documented complication or for a past history of chickenpox only. If the diagnosis is uncertain or another rash is suspected, verify the chart.
Coding tip
Code the documented stage and severity exactly as stated; uncomplicated varicella should not be upgraded to a complication without provider support.