BACKGROUND AND OBJECTIVES: Task shifting between different cadres of health worker has been proposed as an approach to address workforce shortages. Whether such reallocation is a useful strategy for a health system depends on the potential costs and consequences. Too narrow a focus has implications for population health as resources could be incorrectly directed towards inefficient activities owing to important costs and/or benefits being omitted from the evaluation. We aim to identify the key issues when evaluating the value for money of task shifting and review the applied literature to determine whether it is fit for purpose. METHODS: We developed an a priori logic model of task shifting and searched five databases (MEDLINE, Embase, EconLit, Social Sciences Citation Index and CEA Registry) for economic evaluations of task shifting published between 2014 and 2024. We performed forwards and backwards citation searching. We considered the scope of the evaluations with respect to the ability to capture key costs and outcomes of task shifting from the logic model. Reporting quality was assessed using the Consolidated Health Economic Evaluation Reporting Standards (CHEERS) checklist. RESULTS: The rapid review identified 26 studies for inclusion covering 16 countries. Studies evaluated task shifting to community health workers and lay health workers as well as from doctors to radiographers, non-physician clinicians and nurse-midwives. The studies included health costs and outcomes but few included changes in the capacity of the workforce to undertake tasks, access, waiting times, productivity, burden on other staff, patient satisfaction, patient productivity and health equity concerns. There was a predominance for cost-effectiveness analysis to be used to assess the value for money of task shifting but the literature did include a cost-benefit analysis, a cost-consequence analysis and an extended cost-effectiveness analysis. CONCLUSIONS: The majority of studies identified a range of costs and consequences that may only be appropriate for resource allocation under the strong assumption that all longer term costs and consequences would be unaffected by the task shift.