Health policy in both the United States and the United Kingdom has recently shifted toward a much greater concern with disparities and inequalities in health and health care. As evidence for these disparities and inequalities mounts, the different approaches in each country present specific challenges for policy and practice. These differences are most apparent in the mechanisms by which the progress of such policies is measured. This article compares the United States' and United Kingdom's strategies to gauge the challenges for policymakers in order to inform policy and practice. A cross-national comparison of selected measurement mechanisms identifies lessons for policy and practice in both countries.