ICD-10-CM Diagnosis Code Z20.821 - Contact with and (suspected) exposure to Zika virus (original) (raw)

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ICD List 2025-2026 Edition

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  6. 2026 ICD-10-CM Code Z20.821

Contact with and (suspected) exposure to Zika virus

ICD-10-CM Code:

Z20.821

ICD-10 Code for:

Contact with and (suspected) exposure to Zika virus

Is Billable?

Yes - Valid for Submission

Code Navigator:

Z20.821 is a billable diagnosis code used to specify a medical diagnosis of contact with and (suspected) exposure to zika virus. The code is valid during the current fiscal year for the submission of HIPAA-covered transactions from October 01, 2025 through September 30, 2026. The code is exempt from present on admission (POA) reporting for inpatient admissions to general acute care hospitals.

This code describes a circumstance which influences the patient's health status but not a current illness or injury. The code is unacceptable as a principal diagnosis.

  1. Code Information
  2. Approximate Synonyms
  3. Clinical Classification
  4. Tabular List of Diseases and Injuries
  5. Index to Diseases and Injuries References
  7. Code Edits
  8. Present on Admission (POA)
  9. Replacement Code
  10. Patient Education
  11. Other Codes Used Similar Conditions
  12. Code History

The following list of clinical terms are approximate synonyms, alternative descriptions, or common phrases that might be used by patients, healthcare providers, or medical coders to describe the same condition. These synonyms and related diagnosis terms are often used when searching for an ICD-10 code, especially when the exact medical terminology is unclear. Whether you're looking for lay terms, similar diagnosis names, or common language alternatives, this list can help guide you to the correct ICD-10 classification.

Clinical Classifications group individual ICD-10-CM diagnosis codes into broader, clinically meaningful categories. These categories help simplify complex data by organizing related conditions under common clinical themes.

They are especially useful for data analysis, reporting, and clinical decision-making. Even when diagnosis codes differ, similar conditions can be grouped together based on their clinical relevance. Each category is assigned a unique CCSR code that represents a specific clinical concept, often tied to a body system or medical specialty.

CCSR Code: FAC016

Inpatient Default: X - Not applicable.

Outpatient Default: Y - Yes, default outpatient assignment for principal diagnosis or first-listed diagnosis.

References found for this diagnosis code in the External Cause of Injuries Index:

The Medicare Code Editor (MCE) detects errors and inconsistencies in ICD-10-CM diagnosis coding that can affect Medicare claim validity. These Medicare code edits help medical coders and billing professionals determine when a diagnosis code is not appropriate as a principal diagnosis, does not meet coverage criteria. Use this list to verify whether a code is valid for Medicare billing and to avoid claim rejections or denials due to diagnosis coding issues.

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.

Z20.821 is exempt from POA reporting - The Present on Admission (POA) indicator is used for diagnosis codes included in claims involving inpatient admissions to general acute care hospitals. POA indicators must be reported to CMS on each claim to facilitate the grouping of diagnoses codes into the proper Diagnostic Related Groups (DRG). CMS publishes a listing of specific diagnosis codes that are exempt from the POA reporting requirement. Review other POA exempt codes here.

CMS POA Indicator Options and Definitions

POA Indicator: Y

Reason: Diagnosis was present at time of inpatient admission.

CMS Pays CC/MCC DRG? YES

POA Indicator: N

Reason: Diagnosis was not present at time of inpatient admission.

CMS Pays CC/MCC DRG? NO

POA Indicator: U

Reason: Documentation insufficient to determine if the condition was present at the time of inpatient admission.

CMS Pays CC/MCC DRG? NO

POA Indicator: W

Reason: Clinically undetermined - unable to clinically determine whether the condition was present at the time of inpatient admission.

CMS Pays CC/MCC DRG? YES

POA Indicator: 1

Reason: Unreported/Not used - Exempt from POA reporting.

CMS Pays CC/MCC DRG? NO

Z20821 replaces the following previously assigned ICD-10-CM code(s):

Zika Virus

Zika is a virus that is spread mostly by mosquitoes. A pregnant mother can pass it to her baby during pregnancy or around the time of birth. It can spread through sexual contact. There have also been reports that the virus has spread through blood transfusions. There have been outbreaks of Zika virus in the United States, Africa, Southeast Asia, the Pacific Islands, parts of the Caribbean, and Central and South America.

Most people who get the virus do not get sick. One in five people do get symptoms, which can include a fever, rash, joint pain, and conjunctivitis (pink eye). Symptoms are usually mild, and start 2 to 7 days after being bitten by an infected mosquito.

A blood test can tell whether you have the infection. There are no vaccines or medicines to treat it. Drinking lots of fluids, resting, and taking acetaminophen might help.

Zika can cause microcephaly (a serious birth defect of the brain) and other problems in babies whose mothers were infected while pregnant. The Centers for Disease Control and Prevention recommends that pregnant women do not travel to areas where there is a Zika virus outbreak. If you do decide to travel, first talk to your doctor. You should also be careful to prevent mosquito bites:

Centers for Disease Control and Prevention

[Learn More in MedlinePlus]