You would only need to amend if you received the "Savers Credit" on a 8880 form with your 2018 return. If you entered the Roth in 2018 and transfer to 2019 then the Roth contributions that TurboTax tracks for you will be inaccurate, but that can be corrected in 2019.
A Roth IRA contribution does not actually go on a tax return, but you should enter it anyway to:
1) Tell you if your income qualifies you for a contribution and warn you if it does not.
2) Check if your income exceeds the limit to contribute to a Roth.
3) Track your contribution year-to-year if you use TurboTax every year.
4) Add the Retirement Savers Credit if you qualify.
**Disclaimer: This post is for discussion purposes only and is NOT tax advice. The author takes no responsibility for the accuracy of any information in this post.**
