A blank Box 2a on Form 1099-R, and "Taxable amount not determined" means you will have to answer more questions in TurboTax to calculate the taxable amount.
TurboTax will also give you the option to use the Box 1 amount as the taxable amount.
Answer Yes to "Any Periodic Payments? and answer the follow up questions about your pension."
You will see the option to use the Box 1 amount as the taxable amount.
**Say "Thanks" by clicking the thumb icon in a post
**Mark the post that answers your question by clicking on "Mark as Best Answer"
