To estimate rates and settings of low-value imaging among pediatric Medicaid beneficiaries and estimate the associated expenditures.

Retrospective longitudinal cohort study from 2014 to 2016 of children <18 years enrolled in Pennsylvania Medicaid. Outcomes were rates of low-value imaging for 5 conditions identified by diagnosis codes, healthcare settings of imaging performance, and cost based on paid amounts.

Of the 645 767 encounters for the 5 conditions, there were 37 525 (5.8%) low-value imaging services. Per 1000 encounters, there were 246.0 radiographs for bronchiolitis, 174.0 head computed tomography (CT) studies for minor head trauma, 155.0 and 33.3 neuroimaging studies for headache and simple febrile seizure, respectively, and 19.5 abdominal CT scans (without prior ultrasound examination) for abdominal pain. Rates of low-value imaging were highest in non-Hispanic White children and those in rural areas. In adjusted analysis, non-Hispanic White children were more likely to receive a CT scan for abdominal pain, and Black children were more likely to have imaging for bronchiolitis and minor head trauma. For individual conditions, up to 87.9% of low-value imaging (CT scan for minor head trauma) was in the emergency department (ED), with most imaging across all conditions occurring in nonpediatric EDs, up to 42.2% was in the outpatient setting (neuroimaging for headache), and up to 20.7% was during inpatient encounters (neuroimaging for febrile seizure). Outpatient and ED low-value imaging resulted in more than $7 million in Medicaid expenditures.

Among the studied conditions, more than 1 in 20 encounters included low-value imaging, mostly in nonpediatric EDs and for bronchiolitis, head trauma, and headache. Interventions are needed to decrease the future performance of these low-value services.