ICD-10 Guide

Z28.81

Immunization not carried out due to patient having had the disease

BILLABLE STATUSYes

IMPLEMENTATION DATEOctober 1, 2015

LAST UPDATED09/12/2025

Code Description

ICD-10 Z28.81 is a billable code used to indicate a diagnosis of immunization not carried out due to patient having had the disease.

Key Diagnostic Point:

Z28.81 is used when a patient has previously contracted a disease, which provides immunity, thus negating the need for vaccination. This code reflects a significant aspect of preventive care, as it indicates that the patient has a natural immunity that may influence their health status and interactions with healthcare services. Understanding the patient's history of disease is crucial for healthcare providers to tailor preventive measures effectively. Social determinants such as access to healthcare, education about disease transmission, and cultural beliefs about vaccination can also impact the decision to forgo immunization. This code is essential for tracking immunization rates and understanding population immunity, which is vital for public health initiatives.

Code Complexity Analysis

Complexity Rating: Medium

Medium Complexity

Complexity Factors

Requires accurate patient history documentation.
Potential for misinterpretation of previous disease status.
Need for clear communication between healthcare providers.
Variability in disease prevalence and immunity across populations.

Audit Risk Factors

Inadequate documentation of previous disease history.
Failure to update patient records with immunity status.
Misclassification of the disease leading to incorrect coding.
Lack of supporting clinical evidence for the decision not to vaccinate.

Specialty Focus

Medical Specialties

Primary Care

Documentation Requirements

Documentation should include the patient's disease history, any relevant lab results confirming immunity, and discussions regarding vaccination.

Common Clinical Scenarios

Routine checkups where vaccination history is reviewed, and patients are assessed for immunity.

Billing Considerations

Consideration of social determinants such as education level and access to healthcare services that may influence vaccination decisions.

Public Health

Documentation Requirements

Population-level data on disease prevalence and immunity, along with vaccination rates.

Common Clinical Scenarios

Epidemiological studies assessing community immunity and vaccination outreach programs.

Billing Considerations

Focus on tracking health status and vaccination coverage in various demographics.

Coding Guidelines

Inclusion Criteria

Use Z28.81 When

Z codes are used when a patient does not have a current illness but requires documentation for health status
81 should be sequenced appropriately, often following a primary diagnosis related to the patient's health status
Payer requirements may vary, so it is essential to check specific guidelines for coverage

Exclusion Criteria

Do NOT use Z28.81 When

No specific exclusions found.

Related CPT Codes

90460CPT Code

Immunization administration

Clinical Scenario

Used when administering vaccines to patients who have not had the disease.

Documentation Requirements

Documentation of vaccine administration and patient history.

Specialty Considerations

Primary care providers should ensure accurate history is taken to avoid unnecessary vaccinations.

ICD-10 Impact

Diagnostic & Documentation Impact

Enhanced Specificity

ICD-10 Improvements

The transition to ICD-10 has allowed for greater specificity in coding, enabling better tracking of immunization status and disease history, which is crucial for public health monitoring.

ICD-9 vs ICD-10

The transition to ICD-10 has allowed for greater specificity in coding, enabling better tracking of immunization status and disease history, which is crucial for public health monitoring.

Reimbursement & Billing Impact

The transition to ICD-10 has allowed for greater specificity in coding, enabling better tracking of immunization status and disease history, which is crucial for public health monitoring.

Resources

Clinical References

•
CDC Immunization Guidelines

Coding & Billing References

•
CDC Immunization Guidelines

Frequently Asked Questions

When should Z28.81 be used?

Z28.81 should be used when a patient has a documented history of a disease that provides immunity, negating the need for vaccination. It is essential to ensure that this history is well-documented to support the use of this code.

ICD-10 Z28.81 is a billable code used to indicate a diagnosis of immunization not carried out due to patient having had the disease.