In summary, this chapter provides a context for using economic evaluations for behavioral interventions, summarizes the approach for conducting an economic evaluation, and discusses some of the key methodological challenges in doing so. Given the complexities of conducting economic evaluations, it is best to add a health economic researcher to behavioral intervention studies early on to help identify the most appropriate perspective, cost method, and required measures. In addition, research staff will typically need training in finding the most appropriate design for the economic evaluation, as well as in data collection procedures and measures. A cost researcher should also be in routine communication with an intervention team to troubleshoot data collection challenges. In turn, the cost researcher will need to vet findings from the economic evaluation with the research team and stakeholders to craft key discussion points and messaging that can be presented to potential adopters of the interventions studied.