ICD-10 Code for MMR Titer Testing
The appropriate ICD-10 code for ordering MMR titer testing is Z11.59 (Encounter for screening for other viral diseases) or Z01.84 (Encounter for antibody response examination), depending on the clinical context and payer requirements.
Primary Coding Options
For Immunity Screening
- Z11.59 is the most commonly accepted code when screening for immunity to measles, mumps, and rubella in asymptomatic individuals, particularly for employment requirements or pre-vaccination assessment 1, 2.
- Z01.84 may be used when specifically documenting antibody response examination, though this is less commonly accepted by payers 1.
For Occupational Requirements
- Z11.59 is specifically appropriate for healthcare personnel and daycare workers who require documentation of immunity as a condition of employment 1, 2.
- This code applies when ordering measles IgG, mumps IgG, and rubella IgG antibody tests for adults in high-risk occupational settings 2.
Clinical Context for Ordering Titers
When Titers Are Indicated
- Order serologic testing (measles IgG, mumps IgG, rubella IgG) when vaccination documentation is unavailable or uncertain for adults in high-risk settings 2.
- Enzyme immunoassay (EIA) or ELISA are the preferred testing methods over older hemagglutination-inhibition tests 1, 2.
- Any detectable antibody level above the standard positive cutoff indicates immunity 1, 2.
When Titers Are NOT Needed
- Do not order titers if the individual has documentation of 2 doses of MMR vaccine given at least 28 days apart after the first birthday 2, 3.
- Prevaccination serologic screening is unnecessary if direct vaccination is more cost-effective, as MMR vaccine is safe even in immune individuals 1, 2.
- Documented age-appropriate vaccination supersedes subsequent serologic testing results 1.
Common Coding Pitfalls
Documentation Requirements
- Birth before 1957 is generally considered evidence of immunity, except for women of childbearing age regarding rubella and for healthcare personnel 1, 2.
- Physician-diagnosed disease is not acceptable evidence of immunity for rubella, unlike measles and mumps 2, 3, 4.
- Clinical diagnosis of rubella is unreliable and should never be used to assess immune status 1, 2.
Managing Equivocal Results
- Equivocal titer results should be treated as susceptible unless other evidence of immunity exists 2.
- Documented vaccination supersedes serologic results—do not give additional vaccine doses if someone with documented 2-dose MMR vaccination tests negative or equivocal 1, 2.
Alternative Codes for Specific Scenarios
Post-Exposure Testing
- Z20.89 (Contact with and exposure to other communicable diseases) may be appropriate when ordering titers after known exposure to measles, mumps, or rubella 1.
Pre-Employment Screening
- Z02.1 (Encounter for pre-employment examination) can be used in conjunction with Z11.59 when titers are part of occupational health screening 2.