2026 ICD-10-CM Diagnosis Code Z20.9Contact with and (suspected) exposure to unspecified communicable disease

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

ICD-10-CM Z20.9
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

Z20.9 is a billable ICD-10-CM diagnosis code for contact with and (suspected) exposure to unspecified communicable disease. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). The code is not accepted as a principal diagnosis by the Medicare Code Editor. Coders also document this condition as environment contains animals. 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
Z20.9
Billable Status
Yes — Valid for Submission
Code Describes
Contact with and (suspected) exposure to unspecified communicable disease
Short Description
Contact w and exposure to unsp communicable disease
Parent Code
Z20
Contact with and (suspected) exposure to 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 CodeZ20.9Contact with and (suspected) exposure to unspecified communicable disease

Code EditsBilling

Medicare Code Editor checks that affect claim validity for Z20.9.

Unacceptable principal diagnosis
There are selected codes that describe a circumstance which influences an individual's health status but not a current illness or injury, or codes that are not specific manifestations but may be due to an underlying cause. These codes are considered unacceptable as a principal diagnosis.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Environment contains animals
  • Environment contains infected animal
  • Infectious disease suspected
  • Infective encephalitis suspected
  • Infective meningitis suspected
  • Serious reportable event associated with product or device
  • Transmission of infectious agent via medicinal product

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)
      • communicable disease
    • Contact(with)
      • infection
    • Exposure(to)
      • communicable disease

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 No · outpatient Yes

Patient EducationClinical

Infectious Diseases

Germs, or microbes, are found everywhere - in the air, soil, and water. There are also germs on your skin and in your body. Many of them are harmless, and some can even be helpful. But some of them can make you sick. Infectious diseases are diseases that are caused by germs.

The full article covers:

  • What are infectious diseases?
  • What are the different types of germs that cause infectious diseases?
  • How can you get infectious diseases?
  • What are the symptoms of infectious diseases?
  • What are the treatments for infectious diseases?
  • Can infectious diseases be prevented?

Read the full article at MedlinePlus

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

Convert Z20.9 to ICD-9-CMHistory

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

ICD-9-CM
V01.9 Communic dis contact NOS
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 Z20.9Overview

Is Z20.9 a billable code?

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

Can Z20.9 be a principal diagnosis?

No. The Medicare Code Editor rejects this code as a principal diagnosis because contact with and (suspected) exposure to unspecified communicable disease describes a circumstance that influences health status rather than a current illness. Report it as a secondary diagnosis.

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

Under the General Equivalence Mappings, contact with and (suspected) exposure to unspecified communicable disease converts to ICD-9-CM V01.9 (communic dis contact NOS). The mapping is a direct match.