OBJECTIVE: Opioids remain a leading cause of death in the U.S., and time-free from opioid use is a common measure of effectiveness in economic evaluations of opioid use disorder (OUD) interventions. This study reviews the economic evaluation literature on OUD, identify studies that calculated incremental cost-effectiveness ratios (ICER) based on time-free from opioids, and establishes a benchmark for comparison in future research. METHODS: The review examined economic evaluations of OUD interventions published in the peer-reviewed literature from inception to September 2024. ICERs of cost per period of opioid-free time were extracted or calculated from studies meeting the inclusion criteria. Monetary values were converted to 2024 USD, and ICERs normalized to cost per opioid-free year (OfY). Articles were classified by intervention location (U.S vs. International) and economic perspective. RESULTS: Fourteen articles met the inclusion criteria: 8 from the U.S., 4 from Australia, 1 from Malaysia, and 1 from the United Kingdom. Among the U.S.-based studies, the average ICER per OfY for the healthcare sector, the state policymaker, and the societal perspective were $243,053/OfY, $17,674/OfY, and $32,125/OfY, respectively. For international studies, average ICERs for the healthcare sector and societal perspectives were $79,765/OfY and $195,980/OfY. CONCLUSION: Cost per OfY is a widely used metric in economic evaluations due to its relative importance as a measure of clinical effectiveness. However, a universally accepted benchmark for decision-making does not yet exist. This review aggregates data from existing studies that provided this measure, offering an initial step for establishing a cost-effectiveness threshold for cost per OfY.