Yes. When you have an overpayment of state income taxes, you get the choice to either have the overpayment amount refunded to you or apply all or part of the overpayment to next year's state income taxes. This would apply if you think that you will owe extra state income taxes next year (not covered by state withholdings) and would like to apply your overpayment to next year to lower the amount you pay for next year's state income taxes.

So if you want to get a full refund of your state income tax overpayment then you will apply zero "0" to next year's state income tax return.