Form 2210 - withholding total doesn't match W-2

[SN-CO]

I'm working through a potential underpayment penalty on the 2021 Mac Desktop version.  I'm trying to enter my withholdings by quarter.  It says that the total withholdings must match a certain figure that is shown in Form 2210 line 6.  It says not to estimate.  However, this 2210 line 6 figure does not match my W-2 withholdings.  I don't know where that number comes from, so I don't know how to match up my quarterly withholdings.  

[AnnetteB6]

Form 2210 line 6 includes withholding amounts reported on W-2s, 1099s, and anything reported on Form 1040 Schedule 3 line 11 (excess Social Security withheld).  

Take a look at all of your forms to be sure you accounted for all Federal taxes withheld.

[SN-CO]

Thank you!  This helped.  There was excess Medicare taken out and this helped me to find it.  Thank you!