ABSTRACT: Context:The Certified Safe Farm (CSF) intervention program aims to reduce occupational injuries and illnesses, and promote wellness to reduce health care and related costs to farmers, insurers, and other stakeholders.Purpose:To evaluate the cost effectiveness of CSF.Methods:Farms (316) located in a 9-county area of northwestern Iowa were recruited and randomized into intervention and control cohorts. Intervention farms received occupational health screenings, health and wellness screening, education, on-farm safety reviews, and performance incentives. For both cohorts, quarterly calls over 3 years were used to collect self-reported occupational injury and illness information, including costs to the farmers and their insurers.Findings:Annual occupational injury and illness costs per farmer paid by insurers were 45% lower in the intervention cohort ($183) than in the control cohort ($332). Although out-of-pocket expenses were similar for both cohorts, combined costs of insurance and out-of-pocket expenses were 27% lower in the intervention cohort ($374/year per farmer) compared to the control cohort ($512/year per farmer). Within the cohort of intervention farmers, annual occupational injury and illness cost savings were directly associated with on-farm safety review scores. Reported health care costs were $237 per farmer in the safest farms (those farms scoring in the highest tertile) versus $485 per farmer in the least safe farms (lowest tertile).Conclusions:Results suggest that farmers receiving the intervention had lower health care costs for occupational injuries and illnesses than control farmers. These cost savings more than cover the cost of providing CSF services (about $100 per farm per year).