This book introduces readers to the concept of Content-Based Instruction (CBI) through a brief history and countless examples of the many ways this approach can be applied across settings and programs. Whether readers want to deepen their understanding of CBI or get ideas for their own teaching situation, this book provides an overview of CBI and the process of implementing it. The book discusses the three prototype models (theme-based, sheltered, and adjunct), new models (sustained content language teaching, content and language-integrated learning, English-medium instruction, adjunct models, and other hybrid models), and a research-based rationale for using CBI in the classroom. Each section includes reflection questions designed to guide readers to consider how best to implement CBI in their course and program.