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.
This is generally adjusted gross income increased by certain items such as tax-free foreign earned income. MAGI usually is used to determine phaseouts of certain deductions and credits.