A well-prepared workforce is at the heart of delivering high-quality early care and education services. As part of a cross-site evaluation of the Early Childhood Professional Development Program for the U.S. Department of Education, Child Trends conducted a literature review to identify key features of effective professional development for the early childhood workforce. Child Trends researchers also examined the associations between infant-toddler workforce preparation, program quality, and child outcomes through a literature review; and provided a national portrait of infant-toddler workforce preparation and ongoing professional development through secondary analyses of the National Survey of Early Care and Education. Child Trends researchers also contributed to recommendations for revisions to early childhood workforce definitions within the Bureau of Labor Statistics’ Standard Occupational Classification system. Our researchers continue to examine the effects of state policies and funding decisions on the early childhood workforce.