This brief identifies important elements of high-quality early childhood education programs as indicated by research and professional standards. These include: • Early learning standards and curricula that address the whole child, are developmentally appropriate, and are effectively implemented. • Assessments that consider children’s academic, social-emotional, and physical progress and contribute to instructional and program planning. • Well-prepared teachers who provide engaging interactions and classroom environments that support learning. • Ongoing support for teachers, including coaching and mentoring. • Support for English learners and students with special needs. • Meaningful family engagement. • Sufficient learning time. • Small class sizes with low student-teacher ratios. • Program assessments that measure structural quality and classroom interactions. • A well-implemented state quality rating and improvement system. These high-quality building blocks should be the foundation of any early childhood education system. The California policy brief hold particular interest to California. Of the state’s one million preschool-aged children, 493,877 live in or near poverty. Low-income children are most likely to benefit from high-quality pre-k, pointing to the need for California to improve the overall quality of its early learning system.