This United States Department of Defense manual, Multi-Service Tactics, Techniques, and Procedures for Defense Support of Civil Authorities (DSCA) ATP 3-28.1 MCRP 3-30.6 NTTP 3-57.2 AFTTP 3-2.67 CGTTP 3-57.1 February 2021, describes Title 10, United States Code (10 USC), military involvement as the Services operate unilaterally or along with state National Guard (NG) forces in DSCA environments. 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. Domestic emergencies or incidents (including all hazard disaster response operations) present unique challenges for tactical-level commanders who operate under differing legal authorities and chains of command when coordinating and working with local, territorial, state, tribal, or federal authorities. This publication enhances military understanding as Title 10, and Title 32, Department of Defense (DOD) forces work side by side within the typical DSCA command and control architecture and outlines some of the challenges impacting DOD support operations. Working under Title 14 and Title 10, simultaneously, the United States Coast Guard also provides support for DSCA operations.