ICD-10-CM Diagnosis Code Z28.310 - Unvaccinated for COVID-19 (original) (raw)

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ICD List 2025-2026 Edition

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  6. 2026 ICD-10-CM Code Z28.310

Unvaccinated for COVID-19

ICD-10-CM Code:

Z28.310

ICD-10 Code for:

Unvaccinated for COVID-19

Is Billable?

Yes - Valid for Submission

Chronic Condition Indicator: [1]

Not chronic

Code Navigator:

Z28.310 is a billable diagnosis code used to specify a medical diagnosis of unvaccinated for covid-19. 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. Clinical Classification
  3. Tabular List of Diseases and Injuries
  4. Index to Diseases and Injuries References
  6. Code Edits
  7. Present on Admission (POA)
  8. Replacement Code
  9. Patient Education
  10. Other Codes Used Similar Conditions
  11. Code History

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: FAC017

Inpatient Default: X - Not applicable.

Outpatient Default: X - Not applicable.

The following annotation back-references for this diagnosis code are found in the injuries and diseases index. The Index to Diseases and Injuries is an alphabetical listing of medical terms, with each term mapped to one or more ICD-10-CM code(s).

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.

Z28.310 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

Z28310 replaces the following previously assigned ICD-10-CM code(s):

COVID-19 Vaccines

COVID-19 (coronavirus disease 2019) is an illness caused by a virus. This virus is a coronavirus called SARS-CoV-2. In the United States, there are several vaccines that are effective at protecting people from getting seriously ill, being hospitalized, and dying from COVID-19. These vaccines are being used under Emergency Use Authorization (EUA) from the U.S. Food and Drug Administration (FDA). This means that the vaccines have met the FDA's scientific standards for safety, effectiveness, and manufacturing quality that are needed to support authorization.

This page includes details about the vaccines and the vaccination program, including where you can find a vaccine.

Centers for Disease Control and Prevention

[Learn More in MedlinePlus]