The purpose of this paper is to evaluate the usefulness of the American Community Survey (ACS) both for studying respondents’ motivations for moving and for understanding aggregate metropolitan migration inflows. The ACS, conducted annually and with an initial sample size of about 3 million households, is the foremost data source for studying aggregate migration patterns. The survey includes detailed socioeconomic and demographic information on the current characteristics of respondents, and some retrospective information on residence history and life changing events in the previous year, including marriage and labor force data. Using the 2008-2010 ACS 3-year file, we first look at the relationships between current demographic characteristics, life-changing events in the previous year, and migration behavior in the previous year for household-heads. We then use this information to “infer” if household-heads’ motivations for moving were for family, employment, or other reasons. The distribution of household-heads by these “inferred” reasons compared with respondent-reported reasons for moving from the 2009-2010 Current Population Survey (CPS). We conclude the paper by decomposing intra-metropolitan migration and inter-metropolitan inflows from the ACS by the “inferred” reasons for moving. The results suggest many of the ACS retrospective life event measures are highly correlated with migration behavior, however, the expected difficulties with determining causality of these relationships using cross-sectional data are present.