At work, Mr. Shafer offers job interview advice to one student while plotting financial aid application strategies with another. The classroom where he and his colleagues work has notices on the walls about housing and a free Thanksgiving dinner.

But at home over the last two years, he has spent many hours communicating with his current loan servicer, FedLoan, which is part of the nonprofit Pennsylvania Higher Education Assistance Agency. Eventually, he contacted elected officials and the Department of Education’s ombudsman department. The fact that he has had more than one servicer is a big part of what seems to have gone wrong.

As Mr. Shafer tells it, teacher circles were abuzz back in 2007 when the federal public service loan forgiveness program came into existence. Five years earlier, he had consolidated all of his student loans into a single one. At the time, his servicer verified his income and put him into a repayment plan where his payments would grow slowly over time, presumably as his income grew.

In 2007, Mr. Shafer said, he called his servicer at the time, ACS Education Services, and told the company that he wanted to enroll in the public service loan forgiveness program. No problem, he said he had been told, as long as he made his payments on time for 120 months. When ACS exited the federal loan servicing business, his loan moved to Mohela, short for the Missouri Higher Education Loan Authority, in 2012. Nothing, he said, that he heard or saw from Mohela gave him pause.

In 2013, he heard this from a fellow teacher: Once borrowers in the public service loan forgiveness program reached 120 payments, only one servicer, FedLoan, could forgive the remaining balance. So Mr. Shafer did what he needed to do to move his loans there.

It was at that point that things began to go off the rails. Remember that repayment program that Mr. Shafer ended up in back in 2002? It is what’s known as a graduated repayment plan, and if you’re in one, you’re not eligible for public service loan forgiveness. He was supposed to be in one of the income-based plans.

All along, Mr. Shafer said, people at the three servicers told him that his loan was in “good status” when he asked whether he was on track for forgiveness in 2017. The phone representatives at these servicers, however, may have been defining that term more narrowly — namely, that he was merely making on-time payments. It’s also possible that they simply didn’t understand the highly specific requirements of the loan forgiveness program.