After the legislation has passed Congress and after the President has signed the legislation and after the IRS has written the rules, regulations and procedures. And after the IRS has changed any forms or schedules to accept the tax code changes. And after the IRS has approved the changes in the TurboTax program that apply to the tax code changes, then it will be available for the users of the tax preparation software.
This can take anywhere from several weeks to several months before it becomes available.
For those who have not yet filed then they should WAIT for the correction to the program. If they are getting a refund once the correction is in then they should put the return on extension if the fix is not in by 4/15. If they owe then they should pay the new expected balance due with the extension form filed by 4/15.
For those who have already filed they MUST wait for the IRS to fully process their return before amending it ...
The software version of the 1040X is not available yet and will not be available until March 25 at the earliest and it can be efiled which will speed up the processing time frame. You have to wait for it----unless you would like to print the paper 1040X and prepare it by hand to mail in.
https://www.irs.gov/pub/irs-pdf/f1040x.pdf
Expect the IRS to take 4- 6 months to process your amended return.
