You may have a tax credit on your return that decreases when your income decreases. If the credit decreases more than the decrease in your tax, your net tax will increase. You would have to look at your tax return Form 1040 and Schedule 3 to see what changes when you enter the IRA contribution to identify the issue.
To view your form 1040 and schedule 1 to 3:
- Choose Tax Tools from your left menu bar in TurboTax Online while working in your program
- Choose Tools
- Choose View Tax Summary
- See the Preview my 1040 option in the left menu bar and click on it
- Choose the Back option in the left menu bar when you are done