I suggest that you view your tax summary before and after you enter the 1099R.
Depending on the amount of the pension, maybe there just wasn't enough taxes taken out to cover the additional tax on the income.
Your Tax Summary will show your total income, total Taxable income, taxes assessed, payments (how much was withheld and/or payments you made) your refund or amount due.
To get to the Tax Summary:
1. With your TurboTax Return Open
2. Click on Tax Tools from the menu on the left (in Black)
3. Tools
4. Tax Summary
If you see any row items that don't seem to match up to your actual documents, go back through those sections entirely and answer all prompts and questions.
This should help you see how much in additional TAXES are being added by the additional income.
**Say "Thanks" by clicking the thumb icon in a post
**Mark the post that answers your question by clicking on "Mark as Best Answer"
