Four experiments explored the impact of focused-attention mindfulness training on human performance on free-operant schedules of reinforcement. In each experiment, human participants responded on a multiple random ratio (RR), random interval (RI) schedule. In all experiments, responding was higher on RR than RI schedules, despite equated rates of reinforcement. A 10-min focused-attention mindfulness intervention (focused attention) produced greater differentiation between schedules than relaxation training (Experiments 1, 2, and 4), or no intervention (Experiment 3). Focused-attention mindfulness improved learning when the schedules associated with components of the multiple schedule were reversed. This occurred irrespective of whether the focused-attention mindfulness was before (Experiment 2) or after (Experiments 3 and 4) initial training, or whether compared to relaxation (Experiments 2 and 4) or no intervention (Experiment 3). In Experiment 4, following multiple RR, RI training, focused-attention mindfulness increased sensitivity to contingency reversal and did not interfere with previous training in a group that did not receive a contingency reversal. In contrast, relaxation training did not facilitate reversal learning and interfered with previous learning. The results suggest that focused-attention mindfulness improves awareness of operative contingencies by focusing participants on the present, rather than reducing interference from previous learning. (PsycInfo Database Record (c) 2023 APA, all rights reserved).