Objective. We explored methods and potential applications of a systematic approach to studying and monitoring social disparities in health and health care. Methods. Using delayed or no prenatal care as an example indicator, we (1) categorized women into groups with different levels of underlying social advantage; (2) described and graphically displayed rates of the indicator and relativegroup size for each social group; (3) identified and measured disparities, calculating relative risks and rate differences to compare each group with its a priori most-advantaged counterpart; (4) examined changes in rates and disparities over time; and (5) conducted multivariate analyses for the overall sample and “atrisk” groups to identify particular factors warranting attention. Results. We identified at-risk groups and relevant factors and suggest ways to direct efforts for reducing prenatal care disparities. Conclusions. This systematic approach should be useful for studying and monitoring disparities in other indicators of health and health care.