This abbreviation is used to denote the Report of Foreign Bank and Financial Accounts, currently made on FinCEN Form 114 (before 2013, the FBAR filing was made on IRS Form TD F 90-22.1). Any US taxpayer with a bank account in a foreign country is required to file the FBAR for a given tax year if the amount held in the foreign account exceeds $10,000 at any time during that year. This requirement can be triggered if you work in the US for a foreign multinational company that uses a foreign account to hold your retirement plan assets or deferred compensation, your stock option exercise funds, or your unvested shares of restricted stock/RSUs.