Higher education is a gateway to the middle class: in 2007, the average high school graduate earned only $31,000 a year while the average college graduate earned $57,181. Yet, college has become increasingly expensive: tuition and fees at the average public four-year university have increased 88% since the 2000-2001 school year and two out of three college students begin their careers with student loan debt. The American Opportunity Tax Credit Act of 2009 creates a refundable tax credit for higher education expenses up to $4,000 a year. Because the credit is refundable, households with no tax liability are eligible to receive a tax refund under the program. To be eligible for the credit in any given year, a student must complete 100 hours of volunteer service in that year.