The Current Population Survey (CPS), which is currently conducted via face-to-face and telephone interviewing, is the primary source of monthly labor force statistics in the U.S. Because of increasing costs of interviewer-administered surveys and lower response rates, the CPS is undergoing a modernization initiative to add an Internet self-response mode to its data collection. Designing the survey questions in web is a major change and requires extensive pretesting. RTI International and Research Support Services Inc. (RSS) conducted two rounds of usability testing to evaluate how respondents interacted with the prototype instrument in the Census Bureau’s production environment. Testing focused on how participants navigated through the prototype instrument and whether they encountered any issues with the design and usability of the instrument when answering the survey questions. This report documents the findings and recommendations from the usability testing of the CPS prototype instrument.