Communication is a fundamental skill at the core of the Counter- Insider Threat (C-InT) mission. C- InT professionals must be able to communicate effectively with decision makers concerning risk management recommendations. This research note describes the research and development of a communication playbook designed to support C-InT professionals in the prevention and mitigation of insider threats through effective communication. The playbook contains a variety of techniques and exercises designed to improve communication, including purposeful message mapping, empathetic listening, message delivery, collaboration, plain language, and relationship building.