When Ed Morneault returned to college in 2011, two months before his 40th birthday, he didn’t just want a bachelor’s degree — he wanted a raise and a promotion. Morneault, who works as a facilities manager for the U.S. Army outside of Baltimore, first went to college immediately after high school but dropped out to join the Marine Corps. He stopped and started school multiple times, taking courses all around the world but never earning a degree.

This time, though, Morneault was determined to finish. He chose Excelsior College, an online institution that caters to nontraditional students such as those returning to school later in life. It pieced together his multiple transcripts and determined that he needed only seven classes to get a bachelor’s degree in history. He finished that in 2013 — and then kept going. Last December, he earned an MBA from Excelsior at the age of 44.

But even with those two degrees under his belt, Morneault said, he has yet to receive a raise or a promotion. “There’s no advancement at the moment, unless I want to relocate to a different area,” he said.

Morneault was part of a trend in which older students returned to college during and in the years immediately after the Great Recession. In 2007, 1.9 million students ages 40 to 64 were enrolled in college or university either full or part time, according to the National Center for Education Statistics. That number reached 2.3 million by 2011 and then dropped as the economy recovered. For some, the decision paid off, resulting in higher wages or more stable employment. But others, like Morneault, are still waiting.

Some went back to school because of a job loss. Some, such as Morneault, wanted to improve their skills or had hit a ceiling in their current jobs and wanted to advance further. Others wanted to change careers.

“I needed to finish because it’s important for myself and to be able to progress in my career,” Morneault said.

Going to college is never a guarantee of a good job, of course, as millions of young people learned when they graduated in the middle of the recession. But older college students face challenges that many of their younger counterparts don’t.

Many have started and stopped college while younger, with transcripts from at least four or five institutions. That can make them nervous about trying again, said Jeanne Contardo, vice president for regional operations at Excelsior. And at many institutions, they may not be able to get credit for all their previous coursework.

Unlike most students who enter college immediately after high school, older students are often married with children and working full time while attending school part time. They also could be going through a divorce or facing an illness. Another “challenge for adult learners is many of the workplace policies and financial aid policies are not always amenable to part-time students, which most adult learners are,” Contardo said.

A 2014 study based on National Student Clearinghouse Research Center data found that non-first-time students are far less likely to complete their degrees than first-time students. And a 2011 study from Complete College America, an Indiana-based nonprofit group, found that part-time students fare worse than full-time ones: Even factoring in that we would expect part-time students to take longer to finish their degrees, their bachelor’s-degree completion rates are less than half those of full-time students.

Experts agree that finishing the degree — especially a bachelor’s degree — is paramount for older adults who return to college. According to data from the Census Bureau, the median annual wage for a full-time worker ages 35 to 64 with some college but no degree is about $45,000. Those with an associate degree earn a bit more — about $49,000. But for those who finish their bachelor’s degree, the difference is dramatic: Their median earnings are $67,000. (For workers ages 35 to 64 with only a high school diploma, the median is just under $40,000.)

Students who don’t complete their degrees can end up worse off than if they’d never started — struggling to manage debt without getting the boost in pay that can come with a degree. For people who don’t finish their degree, “it was money spent for nothing,” said Wendy Erisman, head of the higher education policy research company Strix Research and co-author of the 2015 report “Adult College Completion in the 21st Century.”

Student debt is a particularly big problem for older students because they have fewer working years left to pay off loans than younger students do. They also could be dealing with financial issues that younger students are less likely to face, such as catching up on retirement savings, raising children or caring for a sick parent.

From 2005 to 2012, the average student loan balance rose more than 70 percent for Americans ages 40 to 49, going from about $16,000 to about $28,000, according to data from the Federal Reserve Bank of New York. Some of that could be parents co-signing loans for their children, but there are still a significant number of older students borrowing for school because of tuition and fee hikes and a deterioration in household income, according to a 2013 report by Wenli Li, senior economic adviser and economist at the Federal Reserve Bank of Philadelphia.

Default rates also are a growing problem for older students. The share of borrowers who are delinquent 90 days or longer on their student loans nearly doubled for those ages 50 to 59 from 6.3 percent in early 2005 to 12.2 percent at the end of 2012, according to data from the Federal Reserve Bank of New York. For people ages 40 to 49, the share of borrowers that are delinquent jumped from 9.4 percent to 16.1 percent over the same period.

Erisman said that for older students, a single bit of bad luck can trip up their ability to finish school or repay a loan. Their car might break down, forcing them to choose between getting it repaired or paying tuition. They could lose their child care provider and have to miss classes to stay home with children. Or their work schedule could change so that they have to be on the job instead of in class. Student loans become due soon after students leave school, whether or not they’ve finished their programs.

“The rules and regulations of student aid programs are cut out more for 18-year-old brick-and-mortar students,” said Megan McClean Coval, vice president of policy and federal relations for the National Association of Student Financial Aid Administrators, adding that policymakers are starting to acknowledge that more students are nontraditional now and that they need flexible financial aid offerings and repayment plans.

Students who do finish school can still run into problems with debt if they earned a degree that isn’t in demand in the labor market. “Job markets are regional, not national,” Erisman said, noting that high-paying energy jobs in Texas, where she is based, have dried up as the price of oil has fallen.

Even when everything goes well, many older graduates still find they must settle for stagnant or falling wages, especially if they’re starting over in a new career. Mike Selinger, 51, of Kansas City already had a bachelor’s degree but returned to school at age 44 after being laid off in 2009 from Sprint, where he had worked for 20 years as a computer programmer. He decided to go into nursing, an in-demand field. “I was fed up with corporate America and saw this as an opportunity to totally change my life,” he said.

He began by getting a Certified Nursing Assistant certification from a local community college, which took 10 weeks. That landed him a job in a hospital. Initially, it meant a steep drop in pay from his corporate job. Going from just over $80,000 annually to $14 per hour (just under $30,000 on an annual basis) was the hardest part, he said. “Everyone looked at me like I was nuts.”

But Selinger said that he doesn’t regret his decision, and it eventually began to pay off. After earning his CNA, he took science prerequisites and applied to nursing school for an associate degree. His income doubled when he completed it in May 2013, at age 48. With additional promotions and overtime pay, he now earns more than $60,000 a year — but he’s gone as far as he can with an associate degree. This spring, he began taking classes toward his second bachelor’s.