Book excerpt: In 2002, the American School Counselor Association presented the ASCA National Model for school counseling programs as a framework for implementing best practices in training counselors to deliver effective evidence-based approaches for K-12 students. Without a unifying theory of practice, school counselors are often uncertain about how to implement the National Model. Considering school counselors' professional role under the National Model, Theories of School Counseling for the 21st Century offers readers a compilation of contemporary, cutting-edge theoretical models to inform the way school counselors practice the art and science of school counseling.