The U.S. Census Bureau is researching and testing new methods to reduce the cost of the 2020 Census while maintaining data quality. One of the most costly components of the 2010 Census was Nonresponse Followup. In this operation, enumerators conducted inperson interviews at housing units that did not return a census questionnaire by mail. For the 2010 Census, enumerators were instructed to visit each of these units up to three times until the case was resolved. Additionally, enumerators were to make up to three contact attempts by telephone. In this paper, we present an overview of current research on determining the number of contact attempts that should be made to nonresponding units with an emphasis on cost containment and improved overall productivity. Rather than the fixed contact strategy employed in the 2010 Census, we consider adaptive approaches that maintain the quality of the data. We present initial results of possible approaches using data from the 2010 Census and discuss the implications of the methods. We also discuss modeling contact probabilities for each hour of the day to support the case management system.