Get your taxes done using TurboTax

the IRS says you can round 50 cents or more up to the next whole $.  49 cents or less down to the next whole $

TT only allows whole $ and rounds automatically according to the above rule.   so if you want to get around this issue round one of the payments.   check what the IRS is showing, I have to doubt the IRS would issue a notice for what at most would be a $2 difference.