A more recent variation of IBR is known as "Pay as You Earn." This program limits payments to 10 percent of discretionary income and offers forgiveness after 20 years of payments. Pay as You Earn is available for loans made under the federal Direct Loan program after October 1, 2011.

After President Barack Obama released a memorandum last year fretting that "too few borrowers are aware of the options available to them," the Education Department streamlined the application process and sent emails to more than 3 million borrowers to publicize the existence of these programs.

Relatively Easy, Readers Say

Several readers wrote on my Facebook page that they found qualifying for IBR to be relatively easy.

"I had no trouble," wrote Clint Lyle of Nashville, Tennessee. "Downloaded the form, filled it out, attached a couple recent pay stubs, and voila! In three weeks I had a very affordable payment. It's a truly wonderful program."

Yet many overburdened borrowers are still in the dark about the program, said Persis Yu, staff attorney for the National Center for Consumer Law, which runs the Student Loan Borrower Assistance site.

"I'm still working with people who don't know that it exists," Yu said.

Other programs tie reductions in student loan debt to volunteer or military service or to jobs teaching, practicing law or providing healthcare in high-need areas.

Those who teach in a low-income elementary or secondary school for five consecutive years, for example, may be eligible to have up to $17,500 in federal student loan forgiveness. Loan repayment assistance programs, available from schools, employers, states and the federal government, help lawyers make their payments. The Equal Justice Works site (http://www.equaljusticeworks.org/)offers information.

Doctors and nurses can get loan forgiveness if they work in areas that lack adequate medical care through the National Health Service Corps and the Nursing Education Loan Repayment Program. The National Institutes of Health's NIH Loan Repayment Programs, meanwhile, repay up to $35,000 per year of student loan debt for people pursuing careers in biomedical, behavioral, social and clinical research.