Background: Nationally, child care providers serve nutritious food to over 4.5 million children each day as part of the federal Child and Adult Care Food Program (CACFP). As implementation of the first major revisions to the CACFP standards occurs in 2017, understanding how to support compliance is critical. Methods: In 2016, surveys were sent to a randomly selected sample of 2400 licensed California child care centers and homes. Compliance with the new CACFP standards and best practices for infants under 1 year and children 1-5 years of age was assessed. Also, compliance was compared by CACFP participation, and between centers and homes. Interviews were conducted with 16 CACFP stakeholders to further understand barriers to and facilitators of compliance. Results: Analysis of 680 survey responses revealed that compliance with most individual CACFP standards and best practices examined was high (>60% of sites). However, compliance with all new standards was low (23% of sites). Compliance was lowest for timing of introduction of solids to infants, not serving sweet grains, serving yogurt low in sugar, and serving appropriate milk types to children. When different, compliance was higher for sites participating in CACFP versus nonparticipants, and for centers versus homes. Although providers indicated few barriers, stakeholders identified the need for incremental and easily accessible trainings that provide practical tips on implementation. Conclusion: Training on a number of topics is needed to achieve full implementation of the new CACFP standards to ensure that young children in child care have access to healthier meals and snacks. (author abstract)