HighlightsThis article describes a cost assessment of a PTO driveline shielding intervention.Considerations for effective occupational safety interventions beyond reductions in injuries or fatalities are described.The financial viability of combining various on-farm services to reduce intervention costs is discussed.Abstract. PTO entanglements are a primary injury concern on U.S. farms, affecting adults and children. These events often lead to severe injury and permanent disability but can be prevented with proper use of PTO shielding. A promising strategy for increasing PTO shielding on farms has been the introduction of user-friendly shielding options by qualified safety specialists. This study looks at the cost-effectiveness of this approach. The cost-effectiveness of this PTO shielding strategy was calculated based on program-related costs, the PTO shield cost, the lifespan of PTO shields, and the number of PTO shields needed to prevent an entanglement. The cost per entanglement prevented was then calculated by dividing the total costs by the number of entanglements prevented in several cost-estimate scenarios. Costs were adjusted for inflation to 2019 dollars. Costs per entanglement prevented ranged from a low of $921,544 (assuming a 10-year PTO lifespan and using 12,487 as the number needed to treat, i.e., to prevent a PTO entanglement, referred to as the NNT) to a high of $18,583,492 (assuming a three-year PTO lifespan and 67,119 as the NNT). The cost per entanglement prevented at the median PTO lifespan of five years and median NNT of 39,802 was $6,612,244. Based on our estimates, the cost-efficacy of increasing PTO shielding using qualified safety specialists differs widely based on the shield lifespan and the number of shields needed to avoid one entanglement. However, if the cost of introducing PTO shields in on-farm visits is coupled with other on-farm services that defray these costs, then the cost-efficacy increases considerably. Keywords: Cost-effectiveness analysis, PTO entanglements, PTO injuries, PTO interventions, PTO shields.