I too was confused by this issue. After e-filing with full electronic payment of taxes due, Turbotax prompted me with this:
"Print and Mail These Forms to the Government. Even though you e-filed, you're still required to print and mail these forms. Don't skip this important step! Your return isn't complete without it."
So then, after clicking the "Print Required Forms" button, Turbotax produced one form, MO-1040V: Individual Income Tax Voucher. But the form instruction says, "When Should I Use Form MO-1040V?
If you have an amount due on an electronically filed return, or do not submit payment in full when you file your income tax return, send Form MO-1040V with your payment."
This looks like a Turbotax glitch for MO State tax e-filing.
