With the support of the Department of Energy’s Building America Program, the Consortium for Advanced Residential Buildings (CARB) conducted a field evaluation of different interior basement insulation strategies in response to many documented cases of moisture accumulation in these types of systems. Equipment was installed to monitor temperature and relative humidity throughout eight assemblies installed side-by-side in the basement of a Chicago area home to assess their moisture performance. This effort was undertaken to gain a greater understanding of the moisture transport mechanisms present in interior insulation systems to aid in the design and implementation of durable, safe, and effective alternatives. Findings indicate that often overlooked construction details can be critical to moisture performance. Exterior insulations systems, though preferable from a moisture standpoint, were not investigated since the extra cost and complications associated with such systems make them relatively unpopular among home builders.