This policy brief explores kindergarten readiness observation and its benefits to local and state level stakeholders; highlights efforts by California counties and other states to measure school readiness; and makes recommendations for moving toward statewide use of kindergarten readiness observation tools. Key points include: (1) Early efforts to improve students' educational outcomes expand lifelong opportunities for children; (2) School readiness data provide families, schools and communities meaningful information to determine how best to help young students succeed; (3) Many states and local counties are utilizing age- and developmentally-appropriate kindergarten readiness observation tools to measure school readiness; and (4) Short and long-term steps toward a statewide kindergarten readiness observation system must include policymakers, early childhood and elementary teachers, parents, school principals and district level administrators, researchers and other stakeholders. (Contains 52 endnotes.) [Funding for this report was provided by the Morgan Family Foundation.]