Almost no one will qualify for a program that forgives the debt of borrowers who have worked in public service for a decade next year, the first year that forgiveness becomes available, the government predicts.

President George W. Bush signed the Public Service Loan Forgiveness program (PSLF) into law in 2007 as a way for student loan borrowers to pursue sometimes low-paying public service jobs, ranging from teaching to medicine, without having to worry as much about their debt.

But when calculating the costs of the program, Department of Education staffers assumed that it’s unlikely borrowers will have made enough payments to qualify for forgiveness the first year it’s available, according to a report released by the Government Accountability Office.

Borrowers doing this work who make 10 years of payments will have the remainder of their debt forgiven. The first cohort of borrowers is theoretically eligible for forgiveness on Oct. 1, 2017, but advocates have been warning that confusion and administrative hurdles related to the program mean that few will qualify for forgiveness next year. The report from the GAO, which investigates how the federal government spends taxpayer dollars, adds to the growing body of evidence that forgiveness likely won’t begin in earnest until the following year.

The GAO recalculated the cost of the program, assuming forgiveness starts the first year borrowers are eligible. That change adds $70 million to the cost of income-driven repayment programs to the government, according to their estimates. In a response to the GAO, the Department disputed this calculation saying they expect $6.5 million in student loans to be eligible for forgiveness during the first year forgiveness is available under the program.

This accounting quirk is one of many the GAO highlighted in its report released Wednesday, which focused on the cost of income-driven repayment programs, the repayment plans federal student loan borrowers can use to make payments tied to their income. If borrowers make payments under the programs for a maximum of 25 years — and a minimum of 10 years for public servants — they can have the remainder of their debt forgiven.

The watchdog claimed in the report that this methodology may be causing the Department to underestimate the cost of these programs by billions of dollars. The GAO estimates that the government will forgive $108 billion in federal student loans taken out between 1995 and 2017 through income-driven repayment programs, which have expanded under Obama’s tenure.

“We must conclude from this report that the Obama administration’s proposals to expand income-based repayment were all based on totally unreliable budget statistics,” said Jason Delisle, a resident fellow at the American Enterprise Institute, a right-leaning think tank.

In a response to the GAO report, Amy McIntosh, the principal deputy assistant secretary at the Department , wrote that the agency generally agreed with the GAO’s recommendations for ways to improve the model for calculating costs of income-driven repayment programs. The Department also plans to work with other agencies, such as the Treasury Department, to come up with improvements.

Still, McIntosh noted the challenges inherent in estimating any costs associated with the roughly $1.3 trillion in outstanding student loans, a task she said the Department takes “very seriously.” Education officials also noted that published estimates of forgiveness amounts could be misleading and overestimate the cost of forgiveness to taxpayers.

“It is important to note that the decisions made (and critiqued in this report) were based on existing staff and systems resources available, assessed impact and consideration for conservatism,” she wrote in the response. “The lifecycle of a student loan is exceedingly complex, with a multitude of projection paths and outcomes.”

Some of the Department’s accounting issues highlighted by the GAO report include: failing to consider how inflation would affect borrowers’ incomes over time, not accounting for possible growth in the IDR program and not taking into account uncertainty in the number of borrowers who might use PSLF -- the GAO notes that a 5% increase in the number of borrowers expected to participate in PSLF would increase the cost of income-driven repayment programs by $4.4 billion.

Delisle, who has argued for years that the cost of these programs to taxpayers would be higher than anticipated, said he was also shocked to learn from the GAO report that the Department didn’t account for Grad PLUS loans — a loan product students can use to attend graduate school — in its estimates until 2015.

That means they likely severely underestimated the costs, he said. Graduate students typically reap the most forgiveness under these programs. The government sets a limit of $31,000 for the typical student on the amount undergraduates can take out in federal loans. Graduate students on the other hand can borrow up to the cost of their programs. That means they stand to have tens of thousands of dollars forgiven if they use income-driven plans.

Delisle suggests the government either reform the loan program so that graduate student loan borrowers can’t borrow as much or change the repayment system so that they’re eligible for less in forgiveness to curb the costs of income-driven plans.

“I think it’s perfectly reasonable that loans that people take out for graduate school should not be afforded the same protections as loans that people take out to go to community college,” he said.

Still, he said the GAO’s report doesn’t justify getting rid of IDR programs, which function as a safety net for borrowers. Some borrower advocates and even the GAO in earlier reports have argued that the government and the private companies it hires to collect student loans have made it too difficult for borrowers to access these repayment programs and avoid default.

In a statement, Ted Mitchell, the undersecretary of Education, highlighted the importance of income-driven repayment programs to borrowers trying to stay current on their loans. He also noted that the Department has proposed reforms to the program that would decrease costs by $49 billion over 10 years. For example, the Obama administration proposed capping the amount a borrower can have forgiven under PSLF in the most recent budget it sent to Congress, but legislators haven’t moved forward on the recommendation.

“Our Income Driven Repayment plans are helping millions of borrowers successfully manage loan repayment, particularly those for whom standard repayment may prove challenging,” Mitchell said in a statement. “IDR plans also help keep borrowers from financial strain and reduce default, which can wreak havoc on struggling families’ credit rating and ability to get back on their feet.”

The Obama administration has taken pains to expand and promote the programs over the past several years. And it doesn’t appear they would be in jeopardy under a new administration. On the campaign trail Donald Trump said he would like to allow borrowers to put 12.5% of their income toward their loans for 15 years and then have the remainder forgiven.