2026 ICD-10-CM Diagnosis Code Z20.820Contact with and (suspected) exposure to varicella

ICD-10-CM Codes›Z00–Z99›Z20-Z29›suspected

ICD-10-CM Z20.820
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

Z20.820 is a billable ICD-10-CM diagnosis code for contact with and (suspected) exposure to varicella. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). Coders also document this condition as exposure to varicella. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Exposure, encounters, screening or contact with infectious disease.

Code Identity

ICD-10-CM Code
Z20.820
Billable Status
Yes — Valid for Submission
Code Describes
Contact with and (suspected) exposure to varicella
Short Description
Contact with and (suspected) exposure to varicella
Same as the full description in the CMS dataset.
Parent Code
Z20.82
Contact with and (suspected) exposure to other viral communicable diseases

Code Classification

ChapterZ00–Z99Factors influencing health status and contact with health services
SectionZ20-Z29Persons with potential health hazards related to communicable diseases
CategorysuspectedContact with and exposure to communicable diseases (Z20)
This CodeZ20.820Contact with and (suspected) exposure to varicella

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Exposure to varicella

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Contact(with)
      • varicella
    • Exposure(to)
      • varicella

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR FAC016
Exposure, encounters, screening or contact with infectious disease
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Chickenpox

Chickenpox is an infection caused by the varicella-zoster virus. Most cases are in children under age 15, but older children and adults can get it. It spreads very easily from one person to another.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert Z20.820 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
V01.71 Varicella contact/exp
Exact Match The mapping is direct, with no qualifiers.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About Z20.820Overview

Is Z20.820 a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report contact with and (suspected) exposure to varicella on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What is the ICD-9 equivalent of Z20.820?

Under the General Equivalence Mappings, contact with and (suspected) exposure to varicella converts to ICD-9-CM V01.71 (varicella contact/exp). The mapping is a direct match.