Your 2018 contributions are entered in the IRA contribution interview which will put it on line 1 on the 8606 form.
The 10990-R interview asks for previous non-deductible contributions before 2018. You were required to file a 8606 form for each year that you had a nondeductible contribution. Box 14 on the last filed 8606 would be entered and that will go on line 2 on the 8606. When lines 1 & 2 are added it accounts for all current and previous non-deductible basis in the IRA.
**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.**
