interest earned on CD's is taxable each year as it is earned, even though interest is not received or credited until a later year. this only applies to CD's with a maturity date of more than 1 year.
box 1 contains the distribution amount and box 2 may contain the taxable amount. sometimes it's left blank because the reporting entity doesn't know if you have basis. if blank, you need to also enter box 1 in box 2 and then by completing form 8606 if you have basis the correct taxable amount will be determined.
