To ensure that all students have sufficient knowledge and skills in science and technology for success in the 21st century, the nation must attract, prepare, and retain well-educated, effective preK-12 science teachers. The National Science Teachers Association (NSTA) considers strong, performance-based science teacher education program and science teacher licensure standards to be essential for all science teachers, including new and recent college graduates and those entering teaching from another profession. This NSTA position paper describes the characteristics of programs preparing teachers of science, and the accreditation and licensure standards for programs preparing teachers of science.