Advances in state education data systems are helping schools understand and meet the needs of learners from early education through college and the workforce. Each state has adhered to key principles for protecting student data privacy. In the report "Lessons in Data Privacy for Education Leaders. Policy Guide," (ED625423) leading experts and practitioners described five key principles for data privacy: (1) a coherent vision for data privacy; (2) coherent legislation; (3) effective data governance structures, training and support for those charged with safeguarding student data; and (4) transparency about their privacy efforts. The case studies presented in this report demonstrate how state leaders can use these principles as guardrails for protecting students' privacy while maximizing the value of student data. Two of the case studies -- those featuring Colorado and Utah -- examine student privacy policies and practices in the state education agency. The third, which features Kentucky, describes privacy policies that operate both in a statewide longitudinal data system and in the agencies that make up that system. Despite differences in data system structure, the principles provide an effective frame for understanding student data privacy.