Actually that's 2017 Schedule A, not the 1040A tax form. I presume you received a 2017 state tax refund. As you clearly itemized your 2017 federal deductions, line 5 included all your state tax payments in 2017. Since you got a refund, too much state tax was thereby deducted from your 2017 income. The IRS handles this by having you add the amount of the refund back into your 2018 income. (No, you can't enter only part of your state tax payments on Schedule A so as to match your actual state tax.) Bottom line: put the correct line 5 number in. You really don't want an IRS nastygram complete with penalties and interest for underreporting to arrive in your mailbox.