In 2016, the U.S. Census Bureau conducted the 2016 American Community Survey (ACS) Content Test to improve the content of the ACS questionnaire. To measure response reliability, the Census Bureau administered a follow-up telephone reinterview, called the Content Follow-Up (CFU), to respondents of the 2016 Content Test. The CFU cost more and had a lower response rate than expected due to operational difficulties and design constraints. To help improve the 2022 ACS Content Test, we examine potential coverage error and nonresponse bias in the CFU reinterview. Specifically, we examine differences in those 2016 Content Test respondents who were eligible for the CFU reinterview and those who were not. For those who were eligible for the CFU, we examine differences between CFU respondents and nonrespondents. We also discuss potential modifications and alternatives to the reinterview.