It depends on the type of account you have:
If your annuity start date is after November 18, 1996, you must use the Simplified Method for annuity payments from a qualified plan. Nonqualified plans (and certain annuitants age 75 or over) must use the General Rule.
If your annuity starting date is before November 19, 1996, you can use the Simplified Method only if ALL the following are true:
1) Your annuity starting date is after July 1, 1986.
2) The annuity payments are for either your life, or your life and that of your beneficiary.
3) The annuity payments are from a qualified employer plan, a qualified employee annuity, or a tax-sheltered annuity.
4) You were under age 75 when the payments began, or were entitled to fewer than 5 years of guaranteed payments.
If you don't qualify for the Simplified Method, then you'll need to use the General Rule.
At the bottom of the Form 1099-R replica is the Simplified Method Worksheet. To elect the Simplified Method, enter the annuity starting date on line 2 of this worksheet.