A couple of items. If you were using the Freedom Edition of TurboTax, you may need to take an extra step before you see an option to amend - try these steps below.
- Log into your account
- Click My TurboTax (or Taxes) and My Tax Timeline
- Scroll down to "Some other things you can do"
- You likely won't see amend/change a return option
- Click "Add a State" instead
- Now, on the next page, you should see an option to Amend your return.
- If you don't see it right there, then click Federal Taxes > Other Tax Situations > Scroll down to Amend Return
Also, make sure you have logged into the correct account if you have multiple accounts. And, it also shows you are asking this question from the desktop software (CD/Download product), so if you changed from online to desktop this year (maybe during filing for one reason or another), then you should be loading up the desktop software and amending from there, not logging into the online program.