Medical schools are asking Congress to reverse the Education Department’s decision to end a program that has allowed borrowers with high debt-to-income ratios to defer interest on their student-loan payments.

In a joint letter sent Monday, the Association of American Medical Colleges and the American Medical Association ask the chairmen of Congress’s education committees to preserve the “debt-to-income pathway” of the federal economic-hardship deferment.

That option allows college graduates with federally subsidized loans to defer interest payments if their total debt is more than 20 percent of their income and their income minus their loan payments equals no more than 220 percent of the poverty level. The option has benefited many medical-school students during the three to eight years they are in residency programs.

In 2007 the average medical student graduated with $140,000 in debt, and the average first-year resident earned less than $45,000, according to the letter. Eliminating the provision, the letter warns, could discourage students from pursuing less-lucrative careers in medical education, research, public health, or primary medicine.

The department announced plans to end the provision at a rule-making session last week, saying the program would cost taxpayers $1.1-billion over the next decade. The decision was generally supported by financial-aid advocates, who said the money could be better spent on needier borrowers. Most medical residents, they pointed out, are on the verge of earning salaries that will easily allow them to repay their loans. —Kelly Field