Automatic milking systems (AMS) are becoming more common in the USA. Limited research has investigated the influence of robot time budget on milk production/robot. To investigate this relationship, we used one year of AMS software daily data (13,018 daily averages; summer 2017 to summer 2018) from 36 free-flow AMS (Lely Astronaut, Lely, the Netherlands) farms in Minnesota and Wisconsin. The MIXED procedure of SAS 9.4 (SAS Institute, Inc., Cary, NC) was used to analyze the data. Daily milk production/robot was the outcome variable and the predictors included in the initial model were failures/robot, successful milkings/robot, failure time, refusal time, milking time, treatment (prep) time, cleaning time, free time, refusals/cow, and cows/robot. Backward stepwise elimination was used to remove nonsignificant factors until all remaining factors had a P < 0.05 in the final model. Farm was used as random effect. Cleaning time and free time were removed from the model. Results are presented as estimates (±SE). Total failures/robot and failure time were both negatively associated with milk production/robot. For each unit increase in failures/robot, milk production/robot decreased by 2.91 (±0.85) kg/d. For each min increase in failure time, milk production/robot decreased by 0.94 (±0.17) kg/d. Refusals/cow and refusal time followed a similar pattern. For each unit increase in refusals/cow, milk production/robot decreased by 69.27 (±3.06) kg/d, and each min spent with refusals resulted in a decrease of 1.05 (±0.17) kg/d of milk production/robot. For each unit increase in milkings/robot, there was an increase in milk production/robot of 2.65 kg/d. For each extra milking min, milk production/robot increased by 0.99 (±0.02) kg/d. Treatment time (min) was negatively associated with milk production/robot (−168.84 (±5.68) kg/d). A larger number of cows/robot was associated with greater milk production/robot (15.18 (±0.36) kg/d). Robot time budget appears to influence milk production in AMS farms; therefore, robot time optimization could improve performance of AMS.