Sorry i missed it was about Schedule A. Ignore my post.
Is 5a too low or too high? 5a doesn’t matter as long as 5b taxable is right.
For each 1099R…….If the gross amount on a 1099R is the same as the taxable amount the gross amount is not included on the "a" line. So line 4a or 5a could be different than all the 1099R forms box 1. And it’s possible for the “a” line to be less than the taxable amount on line b.
