Why is my backdoor IRA to Roth conversion being taxed? I made 2023 IRA contribution in 2023, 2024 contribution in 2024. I converted both contributions to ROTH in 2025.

If you made the conversions in 2025, you will not report the conversion on your 2024 tax return.  This year, all you will need to report is the nondeductible 2024 contribution. The 2024 nondeductible contribution will be added to your total nondeductible basis from 2023, and reported on Form 8606.

Here's how to enter the 2024 contribution in TurboTax Online:

1. Navigate to Federal > Deductions & Credits > Retirement and Investments>  Traditional IRA and Roth IRA > Revisit
2. Continue through interview again, when you are asked Is This a Repayment of a Retirement Distribution? screen, select No.
3. On the Tell Us How Much You Contributed screen, enter what you contributed and select Continue.
4. On the Did You Change Your Mind? screen, select No, then answer the questions on the following screens.
5. You may see the option to make part of it nondeductible, and if so choose to make it all nondeductible. Or, you may see the message Income Too High To Deduct an IRA Contribution, and the full amount of your contribution will automatically be nondeductible.

Here are the full instructions to report a Backdoor Roth: How do I enter a backdoor Roth IRA conversion?