Below is the TurboTax instruction to report this excess contribution withdraw:

1. Figure out which retirement account you want to remove the excess salary deferral from. You can use IRS Publication 560, Retirement Plans for Small Business, to help you decide.

2. Notify the plan administrator (the company or broker that handles your retirement account) that you have an excess salary deferral as soon as possible.

3. Withdraw the funds no later than April 15, 2019 to avoid paying additional taxes on the excess deferral.

4. Report the excess deferral on your 2018 return in the Income section for Retirement Plans and Social Security whether or not you received a Form 1099-R before you file your return. Enter as much information as you can. Report the excess deferral amount in boxes 1 and 2a, and use code P in box 7. Indicate that this is a 2019 Form 1099-R.

5. In 2019, you will probably receive two Forms 1099-R. One reports the excess deferral amount. The other reports the earnings on the excess deferral. Enter both of these forms in your 2019 return, and we'll only add the earnings to your 2019 income

Thank you for clarifying. Do we need to file Form 4852 as a substitute to 1099-R in case our 1099-R will be provided at the end of the year or early next year?

If we file 1099-R with excess distribution next year, how should we indicate in TurboTax that this form has been submitted already last year?

You should compete the form 4852, and you will be prompted to do this in TurboTax.

The code "P" in box 7 on your 2021 form 1099-R will indicate that the distribution belonged in 2020, so it will not appear as taxable on your 2021 tax return.