While traditional theories of sensorimotor processing have often assumed a serial decision-making pipeline, more recent approaches have suggested that multiple actions may be planned concurrently and vie for execution. As most of the evidence for the latter comes from monkeys, here we study concurrent prospective motor planning in humans by recording functional magnetic resonance imaging (fMRI) during a sequence planning task with multiple potential targets. We find that fMRI activity in premotor and parietal brain areas modulates both with the sequence complexity and the number of targets. We test the hypothesis that fMRI activity is best explained by concurrent planning as opposed to the incomplete determination of a single action plan. We devise a bounded rationality model with information constraints that optimally assigns information resources for planning and memory for this task and determine predicted information profiles according to the two hypotheses. When regressing fMRI activity using this model, we find that the concurrent planning strategy provides a significantly better explanation of the fMRI modulation profile. Moreover, we find that concurrent planning is limited for most subjects, as expressed by the best fitting information capacities. We conclude that bounded rational decision-making models allow relating both behavior and neural representations to utilitarian task descriptions based on bounded optimal information-processing assumptions.