I just encountered this for this year's filing (of 2021 in 2022) where the maximal amount was a penny less than my employer provided (1 employer) W2. I reduced the amount by 1 cent to be the maximum and continued to eFile. I believe as described above it's more of an issue if you itemize. I took standard deduction so I'm not even sure if this number would have mattered to me. In any case, reducing it by one cent made TT happy. If this number had been much greater than a penny I would be concerned that my employer accidentally withheld too much and I'd have to get a refund from them I presume...
