The Foreign Account Tax Compliance Act (FATCA) is a United States regime aimed at identifying US persons holding assets outside the United States. It has two main components: an individual-level reporting obligation on Form 8938 for US persons whose specified foreign financial assets exceed defined thresholds, and an institutional regime under which foreign financial institutions report information about US account holders.
Canada and the United States implemented the institutional side through an intergovernmental agreement, under which Canadian financial institutions report relevant account information to the Canada Revenue Agency, which shares it with the United States. For a US citizen living in Canada, FATCA can require Form 8938 reporting in addition to the FBAR. The two filings overlap but are governed by different rules, thresholds, and agencies.