All interest income must be reported on Form 1040, unless there is a special rule that applies (such as interest on U.S. savings bonds redeemed for higher education costs). Thus, whether or not you receive Form 1099-INT, which is only required if interest payments exceed $10, you must report the interest. If interest exceeds $1,500, you must complete Schedule B and then enter the total on Form 1040.
On Form 1040X, you may file an amended return within a three-year period to claim a refund or correct a mistake made on an original or previously amended return.