This publication, Multi-Service Tactics, Techniques, and Procedures for Defense Support of Civil Authorities (DSCA) ATP 3-28.1 MCWP 3-36.2 NTTP 3-57.2 AFTTP 3-2.67 September 2015, describes Title 10, United States Code (USC), military involvement as they operate unilaterally or along with state National Guard (NG) forces in DSCA environments. Military (operating under all authorities) and civilian after-action reports identify the need for expanded joint military and interagency procedures to enhance military and civil interoperability. For effective DSCA operations, active, reserve, and NG personnel operating under differing military authorities should understand the integration of capabilities, duties, and legal limitations as they support state and federal civilian agencies. DSCA domestic emergencies or activities (including all hazard disaster response operations) present unique challenges for the Department of Defense (DOD) because personnel work under differing legal authorities and chains of command when coordinating and working with non-DOD, state, local, and tribal agencies. This publication enhances military understanding as Title 10, USC, and Title 32, USC, DOD forces work side by side in typical DSCA force organizations and outlines some of the challenges impacting DOD support operations. Chapter I provides an overview of how operating in the homeland differs from overseas areas of responsibility. It explains homeland security, homeland defense, and DSCA. This chapter discusses the role of federal military forces and state NG forces. It introduces authorities including: Title 10 and Title 32, USC, and state active duty. This chapter summarizes the National Incident Management System and National Response Framework. It includes a section on basic command and control and illustrates dual status and parallel command structures. Overall, it emphasizes unity of effort with or without unity of command. Chapter II highlights the unique legal and policy considerations associated with DSCA operations. It discusses approval authorities, immediate response authority, disaster response under the Posse Comitatus Act and the Robert T. Stafford Disaster Relief and Emergency Assistance Act (Stafford Act). Furthermore, it addresses rules for using force and intelligence oversight, and using DOD imagery support. Chapter III highlights general planning and execution considerations in a DSCA environment, such as facility availability, evacuation considerations, and communications. This chapter focuses on factors unique to the DSCA mission. Chapter IV provides DSCA environment-specific planning and execution considerations for military forces. This chapter describes and compares the overall responsibility of each key billet and its coordination with civilian counterparts. Additionally, it provides a breakdown of anticipated requirements of a typical operation to a tactical-level staff by phase of operation. Chapter V provides an overview of the environment, impacts, and likely military missions for specific DSCA events, including: wildfires; earthquakes; floods; winter storms; chemical, biological, radiological, and nuclear events; special events; and cyber-attacks. Appendix A provides approval authority and applicable guidance for unmanned aircraft systems and intelligence community capabilities for multiple operations (e.g., DSCA, civil disturbance operations, search and rescue, support of law enforcement agencies and training). Appendix B provides a list of information needed when submitting an incident, awareness, and assessment request in support of DSCA operations. Appendix C organizes additional information requirements, surveys, and capabilities into formats and tables.