The state of California has recently emerged from deep recession and associated reductions in early childhood programs and has moved into a period of reinvestment in child care, preschool, and transitional kindergarten (TK). In fiscal year (FY) 2014-15, the Budget Act included over $273 million for early learning and child development and restored access to 14,297 California State Preschool Program slots. California's FY 2015-16 budget included a further $46.3 million investment to create 9,530 more State Preschool Program slots. Together, the commitments made in the last two budget cycles provided California with 23,827 new slots. While these investments are promising for the future of California's youngest learners, thousands of young children remain unserved. This policy brief examines the remaining unmet need for preschool in California, based on eligibility and enrollment rates in the State Preschool Program and other state- and federally subsidized early learning and development programs. It also identifies the areas of the state with the highest unmet need for quality preschool programs, and makes recommendations about where new State Preschool Program slots should be offered in order to maximize the benefits for children, families, and communities in California. (author abstract)