The application of the foreign tax credit to the net investment income tax (“N.I.I.T.”) has been a recurring battle in courtrooms in recent years. In the most recent installment, the taxpayer in Bruyea v. U.S. prevailed in claiming a foreign tax credit under the Canada-U.S. income tax treaty. The N.I.I.T. is a 3.8% tax on certain items of passive income that is levied on U.S. individuals whose gross income is above certain thresholds. The position of the I.R.S. is that the foreign tax credit cannot be claimed to reduce the amount of N.I.I.T. that is due. In the facts of the case, the Canada-U.S. Income Tax Treaty clearly provided that the foreign tax credit applies to all U.S. taxes based on income whether in existence at the time the treaty came into force or effect or afterwards. Wooyoung Lee explains all.