The validity of the Centers for Medicare and Medicaid Services Hierarchical Condition Category (CMS-HCC) risk scores have been questioned based on observed regional and geographic differences in coding practices and varied diagnosis frequencies – indicating diagnoses may not directly relate to underlying health risk. With the growing use of CMS-HCC risk scores for other Medicare payment programs, including those impacting increasingly smaller groups of health service providers and rural populations, understanding the drivers of regional and geographic differences is vital. Accurately assessing risk promotes accountability and fairness in payment models and extend the utility of risk scores to additional aspects of care. This study will investigate CMS-HCC risk scores between rural and urban beneficiaries using recent data and analyze which factors drive observed differences.