The U.S. EPA’s Environmental Justice (EJ) Collaborative Problem-Solving (CPS) Model represents a systematic, community-based approach for bringing together various stakeholders to develop solutions to address local EJ and public health concerns. This mixed methods evaluation study, using a two-phase explanatory sequential design that allows for qualitative data to build upon initial quantitative results, reports findings from an evaluation of the U.S. EPA’s EJ Academy (EJA) program that was comprised of a curriculum grounded in the CPS Model and designed to build capacity in addressing EJ concerns. As a part of participation, each EJA Fellow directly applied learned skills to implement an EJ community change project. All Fellows across four cohorts of the EJA (2016–2019; n = 67) were invited to participate in this evaluation and were asked to complete a questionnaire (n = 35) comprised of measures to assess the degree to which CPS Model elements were utilized in the design and implementation of their community projects. Interviews were conducted (n = 25) to further explore the utility of the CPS Model in building capacity to address local environmental challenges. In an assessment of the full CPS Model using all seven elements in a composite measure, more than half of the EJA Fellows (n = 19, 55.9%) had moderate levels of implementation of CPS elements and 17% (n = 6) had high levels of implementation into their projects. Evaluation findings provide insight into the impact and limitations of the EJA with implications for future program planning and distribution of the Academy curriculum to assist communities in addressing EJ concerns and making environmental change.