IRS Link to Form — Found Here
Form 8891 was previously used by individuals with retirement plans held in Canada when they were living in America, each time they took distributions. The process proved to be cumbersome for many good-natured Canadians, and caused the IRS a lot of trouble as well.
This form has been retired in favor of an acknowledgement on the IRS Form 1040.
Form 8891 is no longer used, which came as a relief to many Canadian-Americans who had retirement plans from work they did in Canada. Certain filing requirements still exist, such as a new form replacing the FBAR, for foreign bank accounts, now called the FinCEN Form 114.
Otherwise, the IRS will just take things in stride when an Individual’s 1040 reports income from Canadian retirement accounts. Obviously there are many, many people who live in the US but have Canadian retirement benefits.
The IRS and the related agencies realized after years that many people were suffering unnecessarily due to the confusing filing requirements surrounding these plans, and some of them were losing thousands and thousands of dollars of their hard-earned retirement benefits as they hired tax attorneys to plea their case and file for private letter rulings from the IRS.
Of course, if 8891 had been used properly, none of this would have been necessary, but the IRS decided it was not really needed and simply added a line to the 1040 for the Canadians.