OBJECTIVES: Little evidence exists to support the increasing concurrent use of multiple antipsychotics (APs) among children. Case reports suggest that use of multiple APs could lead to an increased risk of delirium, serious behavioral changes, cardiac arrhythmias, and death.  In 2013, the National Collaborative for Innovation in Quality Measurement (NCINQ) proposed a quality measure of concurrent use of multiple (2+) APs among children for use in Medicaid and CHIP programs. The Pharmacy Quality Alliance (PQA) has been working on a similar measure using 3+ APs. The objectives were to analyze the performance in the Mississippi Medicaid program on both the 2+ and 3+ proposed quality measures. METHODS: A retrospective analysis was conducted using Mississippi Medicaid data for July 2013 through June 2014. For both measures the denominator contained beneficiaries ages 0 to 21 as of June 2014, who were continuously enrolled 3+ months and were on any AP for at least 90 days. The numerators contained those beneficiaries who were concurrently on 2+ APs or 3+ APs for a period of at least 90 days during the measurement year. RESULTS: The denominator included 4,435 children who were on at least 1 AP. About 464 (10.5%) and 159 (3.6%) beneficiaries were concurrently on 2+ or 3+ APs respectively. The performance rates on the two measures did not significantly differ for the fee-for-service or two managed care plans.  Also, the performance rates on the measures decreased with an increase in beneficiary age. These results also were consistent across the three health plans. CONCLUSIONS: There is considerable debate about the rate of appropriate concurrent use of 2+ APs in this population.  However, there is no clinical support for concurrent use of 3+ APs.  Although the percentage of children concurrently taking 3+ APs is small, possible drug utilization management actions are needed to further reduce this occurrence.