We examine how U.S. individuals respond to regulation intended to reduce offshore tax evasion. Specifically, we study investment responses to the Foreign Account Tax Compliance Act (FATCA), which requires foreign financial institutions to report information to the U.S. government regarding U.S. account holders. We document a $15.3 billion decrease in equity foreign portfolio investment to the U.S. from tax haven countries after FATCA implementation, consistent with a decrease in “round-tripping” investment activity attributable to U.S. investors’ offshore tax evasion activities. When testing total worldwide investment out of financial accounts in havens post-FATCA, we find a decline of $56.6-$78.0 billion. We also provide evidence of other important consequences of this regulation, including increased expatriations of U.S. citizens and greater investment in alternative assets not subject to FATCA reporting, such as residential real estate and artwork. Our study contributes to both the academic literature on regulation and crime and to the policy analysis of regulation to reduce tax evasion.