Centrider is wrong on at least one point. The credit you are allowed DOES function as a "credit" (to taxes paid) so while you can never get back more than you actually paid, the credit can "potentially" give you the amount of credit back in the form of a refund. Single income over $100K/year, 2 kids, 1 wife and an average mortgage yielded only about a $600 credit of the $2,600 for our '06 HiHy.