Despite the active promotion of cover crops as a key conservation practice, their adoption is very limited. We developed a series of partial budgets based on a statewide survey of Iowa farmers to evaluate the changes in net returns resulting from the incorporation of cover crops into a corn or soybean production system. The average net returns to cover crop use for farmers who did not use cover crops for grazing livestock or forage were consistently negative across different planting and termination methods, tillage practices, and experience levels. Only farmers who used cover crops for grazing livestock or forage and received cost-share payments tended to derive net positive returns from cover crop use. Our results can be used as benchmarks for current or potential cover croppers and for ground-truthing agricultural and conservation policy design.