More than one in five borrowers of federal student loans who attend commercial colleges default within three years of beginning repayment, according to new figures being made available on Monday by the Department of Education.

Historically, the government has reported such figures in terms of how many students default within two years  a figure that stands at 6.7 percent of student borrowers over all and about 11 percent at commercial colleges.

But the new three-year numbers, though preliminary, give a clearer picture of whether a student at a particular college will default, and the government will soon begin using them to help decide which colleges qualify for taxpayer-supported student-aid programs.

Currently, colleges with default rates over 25 percent for three straight years can be disqualified, but experts argued that colleges were manipulating the two-year figures.