Conditional Entrants (CEs) are children who have not received all required immunizations for age or grade but cannot yet receive one or more of their catch-up doses. In 2014, of the 37,000 CEs in California’s kindergartens, 90% failed to meet the criteria for conditional admission and should have been excluded from school until they received the doses that were due at the time of admission. To improve compliance with immunization requirements, California Department of Public Health initiated the Conditional Entrant Intervention Project with local health departments (LHDs). Eight LHDs were targeted; 16 LHDs performed interventions with 161 schools. Following the intervention, compared to the previous year, the proportion of students reported to be CEs in California kindergartens decreased by 2.5 percentage points, from 6.9% in fall 2014 to 4.4% in fall 2015.