Maybe I'm misunderstanding you, but consider this example. Your federal tax liability is $5,000 before your hybrid credit. You are eligible for a $2,000 hybrid credit on your federal taxes. You had $5,000 withheld from your paychecks throughout the year. So, you owe them nothing before applying the hybrid tax credit. However, you do apply the $2,000 hybrid tax credit. This is very simple now. The IRS will be sending you a refund check for $2,000.