There are the usual reasons to be in college, and then there is the one that dumbfounds Julian Gallegos, a business instructor at Community College of Allegheny County.

Every so often, he says, he'll hear from a student who has missed so many classes, or sunk so low in grades that he'll suggest that the student withdraw from the course.

The student pleads to remain, but not out of any love of the subject or any desire for a degree. Rather, it's because dropping the course would sink him below full-time student status, making him ineligible for coverage under his family's medical plan.

"Usually, they don't want to be there," Mr. Gallegos said. "They're there strictly for insurance."

On community college campuses, where tuition is a fraction that of four-year schools, health insurance costs have become an unlikely driver of academic decisions. In some cases, students and their parents have done the math and concluded that a year's tuition isn't much more than the cost to insure a young adult on an independent policy.

Tuition rates at CCAC are near the middle of the state's community colleges at $1,968 a year. By comparison, insurance prices charged for a college-age individual can range from roughly $600 to $2,500 a year or higher depending on one's health history, deductible, co-payment and quality of coverage, according to Highmark, the region's largest insurer.

To be sure, most students enrolled in community college are there for academics, not insurance. And even a student initially inspired by medical coverage can later flourish. But at its extreme, say faculty, the phenomenon is keeping some young adults on campus who sleepwalk through their classes because they enrolled under parental pressure.

"If they do come to class, they stare at the wall," said Tim Pavlik, another business instructor at the college. "Some of these kids quite frankly would be better off getting a part-time job than sitting in a room doing nothing, but they do need health insurance."

In many other cases, it means students who truly want a degree face the added hardship of deciding what courses to take based on reasons other than their own academic interests.

"It's unfortunate," said Mary Frances Archey, interim senior vice president for academic affairs and CEO of South campus. "But it's there."

The issue is a little-discussed aspect of a debate over insurance coverage now before the Pennsylvania Legislature.

Insurers typically allow parents to cover their dependent children until age 19, with extensions of a few more as long as a child is enrolled full-time. One provision of Gov. Ed Rendell's proposed health care reform would mandate that insurers allow parents to keep dependent, unmarried children on a policy until their 30th birthday, regardless of how many courses they take.

Experts say the matter seldom surfaces in policy discussions on how to improve success rates among community college students, partly because there are no data on it. But instructors, counselors and administrators at several campuses from Pittsburgh to suburban Philadelphia all said in interviews the phenomenon was a significant presence at their schools.

Mary McGinnis, a career and academic counselor at Butler County Community College, estimates that insurance is an issue for perhaps 40 percent of the students she speaks with who are in academic jeopardy.

At Northampton Community College, insurance is a consideration for maybe a third of the traditional-age students still on their families' health insurance, said Mardi McGuire-Closson, the school's vice president for student affairs and dean of students. "It's clearly common," she said.

"One of the ways we'll hear about it is when a student has not done well and we are in the dismissal process, and we're not allowing them to come back full-time," said Grant Snyder, dean of student affairs at Delaware County Community College. "You'll hear them say 'I need to be full-time to maintain my health insurance.' "

On CCAC's Allegheny campus, it's not hard to find a student intent on earning a degree who adds classes based on medical coverage, even when a lighter load would have allowed more time to focus on a particularly challenging course.

Lisa Lawler, 24, of O'Hara, who is enrolled in the medical assistant program, said health insurance is the only reason she picked up a course this semester in preschool development. It put her at 12 credits, the threshold at which a CCAC student is considered full-time. As such, she can remain on her family's policy.

"The course really doesn't have anything to do with my major but it's an extra three credits," she said. "I have to be full-time to have insurance."

Second-year student Fatima Trimble, 20, of Collier, who intends to study social work, said she needs more income and would like to go beyond the 20 hours she already puts in at her campus job. But dropping down to a part-time load of nine credits is not an option, she said, because it would force her off her father's insurance.

"There's no way I could pay for it myself," she said. "Otherwise, I probably would drop one because there are some [courses] that I'm just not doing that well in because I'm really busy."

Michael Wentz, 19, of Brookline, said his decision to take a semester off earlier meant his parents ended up paying $155 a month to insure him. He returned to full-time status as a criminology student after his parents suggested he do so. "They said it would really help a lot," he said.

Schools including CCAC will suspend a student for poor academic performance. It can be a wrenching decision if the student is over his or her head out of a need to be insured, and even more so if the student has a health condition that will make self-insuring more expensive.

"You have to separate your compassion for the student's situation from what you know is right," said Allysen Todd, a dean on CCAC's Allegheny campus who chairs a committee that reviews such suspensions.

Nationwide, about 25 percent of college students are believed to be uninsured, said Dana Mills, director of student health service at Marquette University and chair of the student health insurance task force of the American College Health Association.

He and other experts say insurance concerns weigh heavily on students at four-year campuses too, though the problem manifests itself differently in part because residential campuses are more likely to require insurance up front as a condition of enrollment. And higher, four-year tuition rates diminish the economic incentive for adding a course simply for insurance.

Kay McClenney, director of the national Community College Survey of Student Engagement, said she too hears from faculty about the influence of health insurance on enrollment. Her own hunch is it's probably well short of an epidemic and instead yet another example of financial strains that put community college students at greater risk of academic failure.

Insurers say that, in fact, they are working to make policies more affordable for college-age students, who are generally in better health but less likely to be insured if not on a parent's policy. Highmark spokesman Michael Weinstein said insurers' use of full-time status is simply an attempt to distinguish between those who are financially dependent on their parents and those who are more likely to be working and able to afford their own coverage.

Mr. Gallegos worries about the effect a uninterested student has on a class, including one where the grade involves group projects. "Students who are not serious, they're not helping out the group," he said. "I'll hear complaints from other members, 'Where is this member? I haven't seen Johnny in two weeks.' "