Thanks for your quick reply and explanation of Lines 4, 5 &6 Thomas. I totally understand the sequence of all three lines, and that Line 6 is determined by subtracting Line 5 from Line 4. All of that makes total sense to me and has always been accurate for every previous year that our former accountant filed extensions for my wife and I. But, if you follow the logic of what you just confirmed and what we both agree makes sense, deducting Line 5 ($460) from Line 4 ($0.00) can only be Zero, or more accurately -$460, if the IRS algorithms allows for negative numbers on Line 6, which would mean that the IRS owes me an additional $460 dollars. Since Form 4868 clearly doesn't allow for negative numbers on Line 6, then the only result possible on Line 6 is $0.00, if you subtract Line 5 from Line 4, especially when Taxcaster determined that I'm owed a $762 refund for 2021. So, it appears that TurboTax's algorithm has made a glaring mistake, unless Intuit has decided to change the fundamental principles of mathematics. If this portal allowed for attachments, I'd attach the final summary panel from Taxcaster, so you can see the full detail yourself. Regards, Paul
