Assuming that you asked the IRA custodian for a return of excess contribution then they will return the excess plus any earnings. Since the excess was withdrawn in 2019, you should receive a 2019 1099-R with a code "PJ" in box 7, the excess in box 1 and the earnings in box 2a. Because this was a contribution *for* 2018, the earnings are taxable in the 2018 tax year.
That will require amending 2018 to add the 2019 1099-R to the 2018 tax return (TurboTax will ask what year the 1099-R is for - 2018 or 2019). There is no need to amend now before you receive the 2019 1099-R (usually after January 31, 2020). You have 3 years after the April 15, 2019 due date to amend a 2018 tax return, but you should amend ASAP after you have the 1099-R in hand.
Trying to amend prior to receiving the actual 1099-R can lead to errors if the 1099-R is any different than you think it will be.
**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.**
