More than 100 municipalities across the United States have consolidated their police, fire, and emergency medical services into a single, consolidated agency. As initial reasons to consolidate change or diminish, some agencies have deconsolidated, but many remained consolidated. In this work, we use perspectives of contingency theory and institutional theory of organizations to explore why agencies may remain consolidated. Data and insights are drawn from two expert panels and a series of seven case studies. We found contingency theory helps explain why many of these agencies consolidate. We also found, as institutional theory would predict, that many conformed to standards of other bodies or even created their own “cultural” standards. This work highlights the importance of both theoretical perspectives in assessing the growth and persistence of these agencies.