Defense Support to Civil Authorities (DSCA) is the process by which military assets can be requested by civilian authorities, often by state or regional offices of emergency management. This request is in response to critical incidents, including natural and human caused disasters. However, little is understood about collaboration and cooperation between civil authorities and their military counterparts in terms of planning and training, especially in the unique circumstance of National Capital Region (NCR) where there are local, state, and federal civil authorities and military organizations. This is problematic, as a lack of training and preparation may result in delayed response to emergency incidents in the region, which may cause a disruption of government nationwide. Using Sabatier and Jenkins-Smith's advocacy coalition framework, the purpose of this case study of DSCA in the NCR was to gain insight on whether collaborative planning and training between civil and military partners has resulted in effective public policy that will guide decision making in the event of a natural or human caused disaster. Data were collected from a total of 15 participants who represented military and civil emergency managers. These data were deductively coded consistent with the elements of the policy advocacy framework, and then subjected to thematic analysis. Findings indicated that military members have a more thorough understanding of DSCA procedures, where civilian emergency managers had knowledge deficits regarding procedures and policies guiding DSCA support. The positive social change implications stemming from this study include recommendations to civil authorities to collaborate with the Department of Defense related to mobilization procedures and DSCA policies to promote seamless cooperation in the event of a major disaster.