President Obama's tuition tax-credit program has benefited more upper-middle class families than previous programs did, says a new report from Education Sector, a nonpartisan think tank for education reform.

Using Internal Revenue Service data collected by the College Board, the report compared tuition tax breaks from 1999 to 2009, when the president's American Opportunity Tax Credit program was enacted. The program allows families to receive tax credits of up to $2,500 for up to four years per student. Forty percent of the credit, or $1,000, is refundable.

Since the American Opportunity Tax Credit program was enacted, the report says, the amount and share of tax credits have shifted toward wealthier families. After it went into effect, families making less than $25,000 a year or more than $100,000 a year saw an increase in the share of tax breaks they received, while the share going to families making between $25,000 and $100,000 a year declined...