What are the ICD-10 (International Classification of Diseases, 10th Revision) codes for checking titers of Measles, Mumps, and Rubella (MMR), Varicella (chickenpox), Hepatitis B (Hep B), and Tuberculosis (TB)?

ICD-10 Codes for Immunity Screening

For checking titers of MMR, varicella, hepatitis B, and tuberculosis, use Z11.59 (encounter for screening for other viral diseases) for MMR and varicella serology, Z11.59 for hepatitis B serology, and Z11.1 (encounter for screening for respiratory tuberculosis) for TB screening. 1

Specific ICD-10 Codes by Test Type

MMR and Varicella Titers

• Z11.59 is the appropriate code for screening encounters to check measles IgG, mumps IgG, rubella IgG, and varicella IgG antibody titers 1
• This code covers "encounter for screening for other viral diseases" and encompasses all four vaccine-preventable viral infections when ordering immunity titers 1

Hepatitis B Titers

• Z11.59 also applies when ordering hepatitis B surface antibody (anti-HBs) or hepatitis B core antibody (anti-HBc) testing to assess immunity status 1
• Alternative code Z11.4 (encounter for screening for human immunodeficiency virus) may be used in some contexts, but Z11.59 is more specific for hepatitis B screening 1

Tuberculosis Screening

• Z11.1 (encounter for screening for respiratory tuberculosis) is the correct code for TB screening tests including QuantiFERON-TB Gold, T-SPOT.TB, or tuberculin skin testing 2
• This code applies whether using interferon-gamma release assays (IGRAs) or traditional PPD testing 2

Clinical Context for Ordering

When Titer Testing is Indicated

• Order serologic testing when vaccination documentation is unavailable or uncertain, particularly for adults working in daycare settings, healthcare facilities, or educational institutions 1
• The 2021 American College of Rheumatology guidelines note that checking infection titers (measles, varicella, hepatitis B, hepatitis C) prior to starting immunosuppressive medication reached no consensus, indicating this remains a clinical judgment decision 2

Cost-Effectiveness Considerations

• Prevaccination serologic screening is not necessary if it is more cost-effective to simply vaccinate, as the vaccines are safe even in immune individuals 1
• Approximately 90% of US-born adults are already immune to varicella, which may influence the decision to test versus vaccinate directly 1

Common Pitfalls to Avoid

Documentation Requirements

• Do not use diagnosis codes for the actual diseases (e.g., B05 for measles) when ordering screening tests in asymptomatic individuals—these are for active infections, not immunity screening 1
• Ensure the screening code Z11.59 or Z11.1 is used as the primary diagnosis to avoid claim denials 1

Special Population Considerations

• For healthcare workers and daycare employees, these screening codes are particularly important as these populations require documented immunity before patient/child contact 1
• TB screening with Z11.1 should be done prior to starting biologic DMARD therapy and then annually in certain high-risk populations 2

Insurance Coverage

• Using the correct screening codes (Z11.59 for viral titers, Z11.1 for TB) is essential for insurance reimbursement, as diagnostic codes for active disease will not be covered for screening purposes 1
• Some payers may require additional justification codes indicating occupational exposure risk or immunosuppression risk 2