Please see IRS Pub 17 Computations on page 13. I think this also addresses the issue with 1095A.
" Rounding off dollars. You can round off cents
to whole dollars on your return and schedules. If
you do round to whole dollars, you must round
all amounts. To round, drop amounts under 50
cents and increase amounts from 50 to 99
cents to the next dollar. For example, $1.39 becomes
$1 and $2.50 becomes $3.
If you have to add two or more amounts to
figure the amount to enter on a line, include
cents when adding the amounts and round off
only the total."
