Not all amounts reported to you on a 1099-R form are taxable. If you rolled over funds from one IRA to another IRA, for example, you should receive a 1099-R showing how much money you took out of the first account. The IRS wants to know, even though there's no tax due if the money was in the new IRA within 60 days. The Interview for 1099-Rs covers such rollovers. Similarly, part of a payment from an annuity could be tax free. Work through the Interview for IRA, Pension Income, to be sure you don't overpay. If the 1099-R shows that any money was withheld for taxes, you'll need to attach the form to your return if you file on paper.
For more information about IRAs, see Individual Retirement Accounts—IRA.