Because the bankruptcy code never defined “undue hardship,” the courts needed to develop their own definition. Most courts adopted the Brunner test, which originated from a precedent-setting ruling in 1987, in which a woman named Marie Brunner filed for a discharge of her debt less than a year after she completed a master’s degree.

To stop debtors from trying to prematurely cancel their debts, the case laid out a three-pronged test: Individuals must prove they made a good-faith effort to pay the loan by finding work and minimizing their expenses. Debtors must also show they could not maintain a minimal standard of living based on their income and expenses if they had to repay the debt.

But then, in arguably the most challenging prong, the court must consider whether that situation is likely to persist for a significant part of the repayment period — which essentially requires the judge to predict the debtor’s future, ensuring what some courts have described as a “certainty of hopelessness.”

“How do you prove things won’t change for the better in the future?” said Daniel A. Austin, associate professor at Northeastern University School of Law.

Bankruptcy scholars and judges said the test made sense at the time it was adopted because even if debtors could not pass the test, their debts — which were far more modest then — would automatically be discharged in bankruptcy five years after their repayment period started.

But the legal landscape has changed substantially since then. Before 1977, student loans could be discharged in bankruptcy alongside other debts like credit card balances. Congress toughened the law in 1976, adding the five-year period, and again in 1990, when the waiting period was extended to seven years.