After you file

You might have answered a follow-up question incorrectly. 

To enter a conversion in TurboTax Online:

1. Click on "Search" on the top right and type “1099-R”  
2. Click on “Jump to 1099-R”
3. Click "Continue" and enter the information from your 1099-R
4. Answer questions until you get to “Tell us if you moved the money through a rollover or conversion" screen and choose “I converted some or all of it to a Roth IRA”
5. On the "Here's your 1099-R info" screen click "Continue"
6. Answer "Yes" to "Any nondeductible Contributions to your IRA?" if you had any nondeductible contributions in prior years.
7. Answer the questions about the basis from line 14 of your last filed Form 8606 and the value of all traditional, SEP, and SIMPLE IRAs

To enter a conversion in TurboTax Desktop:

1. Click "Federal Taxes" on the top and select "Wages & Income"
2. Click "I'll choose what to work on"
3. Scroll down and click "Start" next to "IRA, 401(k), Pension Plan (1099-R)" 
4. Answer "Yes" to the question "Did You Have Any of These Types of Income?"
5. Click "I'll Type it Myself"
6. Choose "Form 1099-R, Withdrawal of Money from 401(k) Retirement Plans, Pensions, IRAs, etc."
7. Click "Continue" and enter the information from your 1099-R
8. Answer questions until you get to “What Did You Do With The Money” and choose “I moved it to another retirement account”
9. Then choose “I did a combination of rolling over, converting, or cashing out money.” and enter the amount next to "Amount converted to a Roth IRA account"
10. On the "Your 1099-R Entries" screen click "continue"
11. Answer "yes" to "Any nondeductible Contribution to your IRA?" if you had any nondeductible contributions in prior years.
12. Answer the questions about the basis from line 14 of your last filed Form 8606 and the value of all traditional, SEP, and SIMPLE IRAs

Please see How do I amend my federal tax return for this year? Generally, it is best to wait until your original return has been processed before sending Form 1040-X.