A new report from the nonprofit Education Trust finds only five U.S. colleges that properly serve the disadvantaged — by offering a quality education to a significant number of low-income students at a reasonable price.

The report, issued this month, draws this stark conclusion from new federal data on the net price of higher education, after accounting for grant aid.

Dozens — perhaps hundreds — of colleges offer sufficient need-based aid for the neediest students, those with family incomes below $30,200. Those students may pay only a small fraction of the full “sticker” price to attend.

But in EdTrust’s view, most schools don’t do enough. Low-income families received an average of $9,704 in grant aid in 2007, leaving an unmet need of $11,352. That’s about three-quarters of their total income.

The analysis found 275 colleges that require their neediest students to pay more than their total family income to attend.

Affluent families, those earning $115,401 or more a year, paid only 14 percent of their total income, on average, toward college expenses. Middle-income families paid 27 percent of their total income toward college. For many families, that is still a crushing burden.

For true parity, EdTrust argues, a college would have to offer low-income students enough aid so that those families face the same burden as the middle class: college expenses totaling 27 percent or less of family income.

Only 65 colleges offer that much aid.

Among those low-price institutions, only 29 have graduation rates of 50 percent or better. Sadly, many schools with low tuition have low graduation rates, as well. (Institutions with high tuition and strong aid policies tend to have high graduation rates.)

Of those 29 schools, only five serve reasonably large numbers of low-income students. Harvard and Princeton universities, for example, charge only $2,000 or $3,000 in tuition, fees and living expenses to their neediest students — but relatively small numbers of needy students attend those schools. At each of the five schools cited by EdTrust, at least 30 percent of students are disadvantaged.

The five: University of North Carolina at Greensboro, CUNY Queens College, CUNY Bernard M. Baruch College, Cal State Fullerton and Cal State Long Beach.

“It is noteworthy,” the report states, “that none of the highly profitable, for-profit college companies, well-endowed public flagships, or private nonprofits appears among this list of five.”

EdTrust singles out several public flagships and elite schools for remarkably low net prices to needy students. The University of Virginia, for example, charges only $3,904 to low-income students. The University of Maryland charges $6,444. The University of North Carolina at Chapel Hill charges $2,366.

But, again, those schools tend to enroll comparatively small numbers of low-income students, so the benefits are concentrated among a relative few.