Most research on bimanual rhythmic coordination has occurred with the participants in a seated posture. Many activities of daily living, however, require the interaction of standing postural and manual tasks. A population of individuals that are ideal for studying the integration of a manual task into the ongoing control of posture are expert marching percussionists; they have learned to produce rhythmic movements accurately under a variety of temporal and postural constraints. The purpose of the current study was to investigate the integration of bimanual rhythmic movements and posture in expert marching percussionists. Participants (N=11) were recruited from the University of Massachusetts Drumline, and were asked to perform three rhythmic tasks [1:1, 2:3, and 2:3-F (2:3 rhythm played faster at a self-selected tempo)] in one of three postures: sitting, standing on one foot, and standing on two feet. Discrete relative phase, postural time-to-contact, and coherence analysis, were used to analyze the performance of the manual task, postural control, and the integration between postural and manual performance. Across all three rhythms, discrete relative phase mean and variability (SD) results showed no effects of posture on rhythmic performance. The complexity of the manual task (1:1 vs 2:3) had no effect on postural time-to-contact. However, increasing the tempo of the manual task (2:3 vs. 2:3=F) did result in a decreased postural time-to-contact in the two-footed posture). Coherence analysis revealed that the coupling between the postural and manual task significantly decreased as a function of posture (going from a two footed to a one footed posture) and rhythmic complexity (1:1 vs. 2:3). Taken together, these results demonstrate that expert marching percussionists systematically decouple postural and manual fluctuations in order to preserve the performance of the rhythmic movement task.