On line 4 of Form AI2210 you are supposed to enter itemized deductions by period. TT is error checking to be sure that itemized deductions in period 3 aren't greater than itemized deductions in period 4. In my case the amount of allowed itemized deductions in period 3 are greater than in period 4 because the amount of medical deductions allowed is reduced by 7.5% of AGI. My husband and I converted IRAs to ROTH in period 4 and our income went up significantly so that our allowed medical deductions and total deductions went down in period 4. If I enter accurate information into TT, I get the error "Check this entry, Form 2210AI: Line 4C is too large". Nope, that's the real amount of itemized deductions for period 3. It's great that TT does error checking however in this case it's TT that's in error. Last year I found a bug in TT and it was fixed before the tax deadline. I hope this bug will be fixed because otherwise I can't accurately file my taxes.
Are you using the CD/download product or the Online product? I am having trouble creating a test for this using the CD/download product.
I'm using the CD/Download version. I just updated the software. It's Turbo Tax Basic. If I enter a number in 4c any larger than in 4d I get the error. I'm attaching the screenshot.