The federal programs amount to "the broadest and most expansive set of provisions we've ever had" to ease student debt, Terry Hartle, senior vice president of the American Council on Education, told The Washington Post.
Since July 1, student borrowers have been allowed to cap their monthly payments at a modest sum determined by income and family size, the Post reports.
A second plan, the Public Service Loan Forgiveness Program, will completely erase student debt after 10 years for graduates who work for government or various non-profit organizations, the newspaper says.
The income-based repayment deal is available to borrowers with any federally guaranteed loan. The loan-forgiveness program is open only to those with direct federal loans. Neither program applies to private loans.
Legislation authors say they don't know how many of the nation's 30 million student borrowers qualify for the programs.
Student borrowing has risen sharply in the past decade to keep pace with spiraling tuition fees. Total education lending, in inflation-adjusted dollars, rose to $85 billion in 2007-08 from $41 billion in the 1997-98 academic year, the non-profit College Board says.
The average borrower leaves college owing more than $22,000.