Periodic measurement of the size and behaviors of the Jewish population is of vital importance to Jewish communal planners, both nationally and in communities throughout the United States. Methodological design decisions, such as the choice of a sampling frame, mode of data collection, nonresponse follow-up protocols, and definition of eligibility can have significant impacts on population estimates. This paper demonstrates how two studies, one national and one for the Jewish Federation of Greater Philadelphia used the current state-of-the-art address-based sampling methodology and other methodological improvements to significantly increase coverage and reduce bias in the survey results compared to other methodologies.