Access to affordable housing and equitable neighborhoods remains one of the most pressing challenges in modern urban life. Policymakers have long sought to enable low-income households to access neighborhoods offering better schools, safer environments, and stronger economic opportunities. However, such mobility-oriented initiatives can inadvertently disrupt local housing markets or even exacerbate existing inequalities. This study examines the effects of the Small Area Fair Market Rent (SAFMR) policy on the geographic distribution of Housing Choice Voucher (HCV) usage and on local housing prices across U.S. metropolitan areas. SAFMR represents a policy shift from metropolitan-wide rent subsidy standards to ZIP code-level adjustments, with the goal of expanding voucher-holder access to high-opportunity neighborhoods. Using a difference-in-differences framework and a rich panel of housing and voucher data, we document the policy’s heterogeneous impacts across neighborhood opportunity levels, housing price tiers, Gini index levels, and voucher household concentrations. We find that SAFMR led to overall price declines in high-opportunity neighborhoods, though low-tier housing appreciated while high-tier segments declined. In low-opportunity neighborhoods, medium-tier housing saw the sharpest declines, while low-tier units gained modestly. Negative effects were most pronounced in high-opportunity neighborhoods with high income inequality, while large annual increases in voucher households led to price gains in high-opportunity areas but declines in low-opportunity ones. These findings underscore that the success of mobility-oriented housing policies needs the presence of complementary interventions to stabilize vulnerable submarkets and prevent spatial inequality.