U.S. colleges such as Boston University are using financial aid to lure rich students while shortchanging the poor, forcing those most in need to take on heavy debt, a report found.

Almost two-thirds of private institutions require students from families making $30,000 or less annually to pay more than $15,000 a year, according to the report released today by the Washington-based New America Foundation.

The research analyzing U.S. Education Department data for the 2010-2011 school year undercuts the claims of many wealthy colleges that financial-aid practices make their institutions affordable, said Stephen Burd, the report’s author. He singled out schools -- including Boston University and George Washington University -- that appear especially pricey for poor families.

“Colleges are always saying how committed they are to admitting low-income students -- that they are all about equality,” Burd said in a phone interview. “This data shows there’s been a dramatic shift. The pursuit of prestige and revenue has led them to focus more on high-income students.”

The New America Foundation is a nonprofit, nonpartisan public policy institute. Its president is Steve Coll, a former Washington Post managing editor who will become dean of the Columbia University Graduate School of Journalism in July. Its chairman is Eric Schmidt, executive chairman of Google Inc., the Mountain View, California-based search-engine company.

‘Merit Aid’

To increase their standing on college rankings, more private colleges are giving “merit aid” to top students, who are often affluent, while charging unaffordable prices to the needy, according to the report. The percentage of students receiving merit aid jumped to 44 percent in 2007-2008 from 24 percent in 1995-1996, the report found. To a lesser extent, public universities are using some of the same practices, Burd said.

Many of the most selective and wealthiest colleges, including the eight members of the Ivy League, Williams College in Williamstown, Massachusetts, and Cambridge-based Massachusetts Institute of Technology, award aid based only on financial need. Less selective nonprofit colleges often offer tuition reductions and merit aid to lure students to fill their seats.

Boston University charges students whose families earn $30,000 or less an average “net price” -- or costs after scholarships -- of $23,932 and George Washington University, $14,670, the report said. Both offer merit scholarships, which aren’t based on need, according to their websites.

Recruiting Poor