Why can’t I amend my return and it is already accepted

If you filed, it is like dropping it into a mailbox - you cannot get it back.

You'll have wait until your return is either accepted or rejected.

• If rejected, you can make any necessary changes.
• If accepted, you'll need to amend your return. 
• To avoid unnecessary delays, do not amend until your original return has been fully processed.  You will need to print and mail the amendment.  
• Allow 8-12 weeks for processing.

See this TurboTax FAQ for help with amending.

You can check the status of your amended return here, but allow 3 weeks after filing for it to show up.

My return WAS already accepted both Federal & State and it still will not let me amend it. It is telling me I will be paid for my return around 3/5/21, but then telling me I cannot amend it until 3/25/21. This is absurd. I should be able to amend it at any time, even after it was accepted without delay to make sure all the information is correct. 

You are not able to amend your return at this time because Form 1040X, is not available yet. It is currently scheduled for release on March 25. You can monitor the availability of the form via the below link:

IRS forms availability table for TurboTax individual (personal) tax products

@JJDutra1