An IRS form that should be completed by any U.S. citizen or resident who participates in or receives annuities from a documented Canadian retirement savings plan or income fund (RRSP and RRIF). Form 8891 can be used to report any contributions made, gains accrued but not spread and distributions received from these strategies, but mostly it"s used to elect to defer U.S. tax on your RRSP or RRIF.