A new report sheds light on the “adjunctification” of community colleges, which may be a barrier to college completion.

More than half the nation’s most vulnerable college students are in courses taught by part-time, adjunct faculty members who lack the job security, credentials and experience of full-time professors – as well as the campus support their full-time peers receive.

Community colleges rely on part-time, “contingent” instructors to teach 58 percent of their courses, according to a new report from the Center for Community College Student Engagement. Part-time faculty teach more than half (53 percent) of students at two-year institutions.

Students who need the most help and are the least likely to succeed in college in particular lack access to full-time professors. That’s because fully three-quarters of faculty members who teach remedial courses are employed part time.

“It confirms our worst fears,” Kay McClenney, the center’s director, said of the report. The profile of remedial instructors is particularly disturbing, she said. “We’ve got work to do.”

The study is the first extensive, data-rich look at the adjunctification of a sector that enrolls 45 percent of the nation’s undergraduates.

There is a growing awareness in the academy about the challenges part-time faculty face, as well as how those problems might affect students. But the conversation often focuses on four-year institutions and largely ignores community colleges, said McClenney.

Part-time instructors typically earn less and receive little if anything by way of benefits such as health insurance. As a result they have become a “fundamental feature of the model that sustains” community colleges, the report said. That’s because as public funding covers ever-smaller portions of their budgets, two-year institutions have cut costs by hiring more contingent faculty.