The estimated availability of form 1040X is now 2/22/19 but it has been moving out. I suggest you track availability using this link: https://care-cdn.prodsupportsite.a.intuit.com/forms-availability/turbotax_fed_windows_individual.htm...
You should not be preparing and filing an amended return until you receive your refund from your original return. If the refund amount from the original return is wrong, your amended return will be messed up. The IRS sometimes changes the refund amount on the original return before the IRS sends it to you.
