Understand that entering zero means zero but it is perfectly logical for a user to enter zero -- meaning nothing -- and the software acccepts it.
Correction: there is no problem in CA if 2a is left blank for all four 1099-R.
But your software needs to reconcile what happens when zero is plugged into 2a! Again, zero is obviously incorrect but when an amount is asked for and the box is blank, zero is a very logical entry. Software should warn when zero is entered and 2b is checked.
