​​​As detailed in the report, "Agility in Action: A Snapshot of Enhancements to the American Community Survey" (Census Bureau, 2015), the Census Bureau is investigating ways to reduce the difficulty and length of the American Community Survey (ACS) using administrative records to address concerns about the burden survey participation places on respondents. This report addresses the Residence One Year Ago (ROYA) question, and whether it can be replaced or supplemented with data from the Internal Revenue Service (IRS) tax returns. The ROYA question on the ACS has two parts; the first part asks if a respondent has moved in the past year and the second part asks for detailed address information on that move. The research described in this report will begin the determination of whether IRS data provides sufficient coverage and quality that would allow the ROYA question on the ACS to be removed. Alternatively, we may find the IRS data sufficient only to supplement mobility data provided by respondents by filling in missing responses or improving editing routines. A Census Bureau team will use this report and conduct additional research to make recommendations on whether the ROYA question is a good candidate for removal or supplementation with the use of external data sources in its place.