Objective: Many studies view factors related to caseworker burnout as unchanging throughout a caseworker’s career. This assumption may be unfounded, as there is considerable variation in levels of expertise and need for support among caseworkers over the course of a career. To that end, we used the Copenhagen and job demands-resources models of burnout to examine how factors associated with client- and work-related burnout among caseworkers vary by length of employment. Method: We divided a sample of 1,823 caseworkers into 4 length-of-tenure cohorts. We then conducted multivariate linear regressions and cross-model z-tests to examine ways in which job demands and resources related to burnout differed by cohort. Results: Job stress and time pressure were positively associated with at least one form of burnout regardless of tenure; the strength of this relationship varied across tenure cohorts. Supervisor support and training utility were only related to burnout among caseworkers who worked in their agency for less than 2 years. Self-care was negatively associated with burnout regardless of tenure. Conclusions: Caseworker tenure may influence the link between job demands/resources and burnout. Implications for the development of burnout prevention strategies and future research are discussed.