The American Housing Survey (AHS) is the most comprehensive source of information about the characteristics and condition of the nation’s housing stock. AHS respondents have provided detailed information about mortgages for owner-occupied units. This study is intended to determine what types of mortgage market analysis can be supported by the AHS, what areas of the AHS are problematic for mortgage research, and what analysis techniques or changes in the survey could potentially compensate for these problems. First, to test the reliability of the AHS variables, we replicate measures of mortgage activity from other reliable data sources that serve as benchmarks for the AHS estimates. This analysis is referred to as the “replication analysis.” Second, we use the longitudinal nature of the AHS to determine whether answers to questions on mortgages are consistent and stable over time. Based on the research conducted for this study, we have identified several potential modifications to the AHS that would make it substantially more useful for research on mortgage market issues.