BW737, was your contribution made in January 2020 made for 2020 or for 2019? If you told the IRA custodian that the January 2020 contribution was for 2019, can you ask your IRA custodian to change the designation of that contribution to be a contribution for 2020 instead of for 2019?
Assuming that the January 2020 contribution was made for 2020, that $6,000 addition will factor into the calculation of any earnings required to be distributed with the return of the excess $1,346 contribution for 2019. The earnings will add to your 2019 modified AGI and would increase the amount of excess contribution that needs to be returned. CFR 1.408-11 describes how to add your $6,000 January 2020 contribution in determining the adjusted opening balance for the calculation of the earnings attributable to your excess contribution made for 2019.
