This study uses a framework developed using the perspectives of internal and external organizational factors, and emergency management capacity to study the drivers of emergency management collaboration (i.e., vertical, horizontal-interlocal, and horizontalintersectoral collaborations) at the local level. Qualitative data were collected by interviewing county and city emergency managers in Florida to understand practical collaborative activities in both vertical and horizontal contexts, explore county and city managers' rationales behind each type of collaboration, and examine the influences of selected drivers in the theoretical framework. The findings show that for local governments, seeking resources and training opportunities can explain a large proportion of why they seek vertical collaboration. However, in horizontal collaboration, local governments go beyond resource- seeking to also providing assistance to their governmental and non-governmental partners. Horizontal collaboration is more common and more popular than vertical collaboration. In sum, this study helps us gain a theoretical and practical understanding of local emergency management in the United States.