Poverty scholarship in the United States is increasingly reliant upon the Supplemental Poverty Measure (SPM) as opposed to the Official Poverty Measure of the United States for research and policy analysis. However, the SPM still faces several critiques from scholars focused on poverty of non-metropolitan areas. Key among these critiques is the geographic adjustment for cost of living employed in the SPM, which is based solely upon median rental costs and pools together all non-metropolitan counties within each state. Here, we evaluate the current geographic adjustment of the SPM using both microdata and aggregate data from the American Community Survey for 2014-2018. By comparing housing costs, tenure, and commuting, we determine median rent is likely an appropriate basis for geographic adjustment. However, by demonstrating the wide variability between median rents of non-metropolitan counties within the same state, we show that the current operationalization of this geographic adjustment is sorely lacking.