The Handbook of Research on K-12 Online and Blended Learning is an edited collection of chapters that sets out to present the current state of research in K-12 online and blended learning. This volume attempts to synthesize existing research; in doing so, it will act as an important resource for those interested in this topic. However, there are always new studies, concepts, and domains within K-12 online and blended learning. Therefore, we ask readers to think of this work not as a completed product but rather a flowing conversation. Each section includes potential new areas for growth in understanding practice, policy, and research. We encourage authors to contact us at handbookresearch@gmail.com to propose missing research studies for certain chapters or for proposals on new chapters for future volumes. We look forward to hearing from readers and continuing this important conversation regarding K-12 online and blended learning research.