While the dorsoventral and mediolateral organization of the striatum has resolved clear functional distinctions, less is known about how striatal function differs across the anterior-posterior (AP) striatal axis. The focus of this thesis is to delineate the anatomical and functional differences between the anterior and posterior subdivisions of the dorsomedial striatum (DMS), a key region for value-based choice. We begin by reviewing the relationship between anatomy and function that distinguish the various striatal subregions. We further contextualize these subregions by mapping key functional studies onto a mouse brain atlas to reveal that much of the striatal literature is concentrated around a few coordinates along the AP axis. We highlight some of the anatomical and functional studies that have found AP differences and suggest new terminology to identify striatal subregions. We then explore striatal differences within the DMS by comparing population neuronal activity and function within anterior (A-DMS) and posterior (P-DMS) subregions while mice operantly seek reward. Neural recordings show that P-DMS encoded action values and strategy information prior to choice selection while the A-DMS encoded recently selected choices and their anticipated values. The effects of optogenetic perturbations were consistent with these temporally distinct coding properties as unilateral manipulation of the P-DMS prior to choice biased choice contralaterally in a value-dependent manner, whereas unilateral inhibition of the A-DMS following choice impaired future value-based action selection. Using anterograde tracing, we found that the A-DMS and P-DMS projected to a common region within the ventromedial substantia nigra pars reticulata, which contained value-related signals combining aspects of upstream DMS processing. Together, our results support a model for temporally distributed influence on value-based choice across the anterior-posterior axis of the DMS and other striatal subregions. The subsequent study looks at a potential role for dopamine in modulating DMS activity to influence the explore-exploit tradeoff. We used the GRAB-DA dopamine sensor to measure dopamine release as mice performed a 3-arm bandit task, but failed to find dopaminergic influence over the explore-exploit tradeoff.