© 2014, Association of Schools and Programs of Public Health. Objective. This study presents reliability and validity findings for the Assessment for Disaster Engagement with Partners Tool (ADEPT), an instrument that can be used to monitor the frequency and nature of collaborative activities between local health departments (LHDs) and community-based organizations (CBOs) and faith-based organizations (FBOs) for disaster preparedness, response, and recovery. Methods. We used formative research to develop the instrument by ranking LHDs according to their disaster outreach and engagement activities. We validated the scale through a 2011 national survey of disaster preparedness coordinators (n=5273) working in LHDs. We reduced the original measure of 25 items to a final measure comprising 15 items with four dimensions: (1) communication outreach and coordination, (2) resource mobilization, (3) organizational capacity building, and (4) partnership development and maintenance. We used internal consistency reliability m correlation and factor analysis to validate the measure. Results. Using internal consistency reliability, we found reasonable inter-item reliability for the four hypothesized dimensions (Cronbach’s alpha: 0.71–0.88). These four dimensions were confirmed through correlation and factor analysis (Varimax rotation). Conclusion. Higher scores on all four dimensions of ADEPT for organizational respondents suggest that more activities were conducted for inter-organizational preparedness in those organizations than in organizations whose respondents had lower scores. This finding implies that organizations with higher ADEPT scores have more active relationships with CBOs/FBOs in the realm of preparedness, a key element for creating community resilience for emergencies and disaster preparedness.