The purpose of the 2020 Post-Enumeration Survey (PES) was to measure the coverage of the 2020 Census.

The PES was designed to measure the coverage of housing units and people, excluding group quarters, people residing in group quarters, and areas of remote Alaska. It provided estimates of net coverage and components of coverage, including correct enumerations, erroneous enumerations, whole-person census imputations, and omissions. Since the PES was an evaluation, its results did not affect the 2020 Census results.

The Initial Housing Unit Followup (IHUFU) operation was the second PES field operation conducted.

Prior to the start of IHUFU, Initial Housing Unit computer and clerical matching occurred. In the IHUFU operation, addresses that met predetermined criteria from the Independent Listing operation and the preliminary census address list were followed up in the field to collect additional information to determine their unit status, match status, or both. Field staff used follow-up paper forms to collect the necessary information. 

This assessment report focuses on the IHUFU operation and identifies lessons learned. Other PES matching and data collection operations are addressed in separate reports. It provides information on the successes and shortcomings of the 2020 PES IHUFU operation and produces valuable data for the 2030 PES planning cycle.