I am not clear on what you are billing. Usually, each vaccine/toxoid product code is billed with one unit. See the administration codes (90460-90474) to bill separately for the administration. If billing for state-supplied vaccine under Vaccines for Children program, see your state’s reporting requirements.

If your units shown are for the administration with physician/QHP counseling to a patient under 19 years old, you have 4 units of 90460 (one for the first or only component in each vaccine product) and 2 units of 90461 for the 2 additional components in the MMR vaccine. If no physician/QHP counseling was provided to the patient/caregiver or patient was 19 or older, bill one unit for each vaccine product using 90471 (4 units).

Hope that helps.
Cindy