Some annuities report to you on the 1099R the distribution received (box 1) and the taxable amount of it (box 2a). It just needs to be entered in completion and it is completed. In this case, the difference between the two boxes may be the amount reported in box 5.
Some annuities are reported to you on the 1099R and you have to provide the cost basis and use the simplified method in order to determine the taxable and nontaxable portion.
Please clarify more details on the type of annuity it is, the payer of the annuity, and whether or not the boxes 2a and 2b and 5 are completed.
If box 2a is blank and the box for "taxable amount not determined" is marked, then you may need to use the simplified method to calculate the taxable amount.
