ICD-10-CM 2027
ICD-10 code for varicella exposure
From the official ICD-10-CM alphabetic index entry “Exposure (to) › varicella”. Page updated September 29, 2026.
About coding varicella exposure
The ICD-10-CM code for varicella exposure is Z20.820 (Contact with and (suspected) exposure to varicella).
Within Z20.82 (contact with and (suspected) exposure to other viral communicable diseases), Z20.820 is specifically for contact with and (suspected) exposure to varicella. Related codes cover Zika virus (Z20.821), COVID-19 (Z20.822) and other viral communicable diseases (Z20.828).
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
In MS-DRG v44.0, it is part of the grouping logic for DRG 795 (Normal Newborn, relative weight 0.2022) and DRG 951 (Other Factors Influencing Health Status, relative weight 0.5577), in MDC 15 (Newborns and Other Neonates with Conditions Originating in the Perinatal Period) and MDC 23 (Factors Influencing Health Status and Other Contacts with Health Services), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
Common questions about varicella exposure ICD-10 codes
What is the ICD-10 code for varicella exposure?
- Z20.820 — Contact with and (suspected) exposure to varicella.
Is Z20.820 billable?
- Yes. Z20.820 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can Z20.820 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict Z20.820 as a principal diagnosis.
Is Z20.820 a CC or MCC?
- No. Z20.820 is neither a CC nor an MCC under MS-DRG v44.0.