You should not try to amend your return
until it has been fully processed and you have received your refund or your
payment has cleared.
Amended returns do
not “catch up” to your original return and replace them; they are processed as
two separate returns.
Changing any information in the online
account after you have filed your original tax return does not amend your
return. If
you are due a larger refund than on your original return, your amended return
should only show the difference and you will receive a separate check for it.
If you owe money on your amended return, it will show only the new amount
owed, you will have to mail a check with the return
An amended return, Form 1040X, can only
be printed and mailed to the IRS, it cannot be e-filed. The IRS will take
up to 16 weeks or longer to process an amended tax return.
Before starting to amend the tax
return, wait for the tax refund to be received or the taxes due to be paid and
processed by the IRS.
See this TurboTax support FAQ on
amending a tax return originally completed using TurboTax -https://ttlc.intuit.com/questions/1894381-how-to-amend-change-or-correct-a-return-you-already-filed
