As Katie Podson's friends headed off to colleges like Princeton and the Massachusetts Institute of Technology two summers ago, they fretted over the path their fellow Mount Hebron High School honor student had chosen. "Katie," she recalls them saying in encouraging tones, "you know you can go to a four-year school."

She knew. But Podson also knew that she wasn't ready to leave home for a fast-paced university or to start racking up tuition debt. Thus the decision that shocked her friends: choosing to enroll at her local community college.

"I needed the smooth transition. This was it," explained the 20-year-old Ellicott City native, who said she plans to transfer from Howard Community College to a four-year institution in the fall to complete her degree in special education.

Whether shut out of universities in a competitive admissions climate or turned off by their soaring costs and oversize classes, unprecedented numbers of ambitious, high-achieving students are shrugging off the "13th grade" stigma and going to community colleges.

In Virginia, officials project that community college enrollment will grow by 20,000 students -- about 13 percent -- between now and 2010, many coming right out of high school and attending classes full time. Maryland officials expect the number of full-time undergraduates at two-year colleges to increase by 30 percent over the next decade, compared with 15 percent at four-year campuses.

These trends will continue to accelerate, educators say, as a record number of graduates emerge from the nation's high schools by the end of the decade and find state universities and private colleges that are already bursting at the seams.

The influx of degree-hungry teenagers is already transforming the culture of schools more accustomed to a part-time population of working adults. At Howard Community College, where the median age has dropped from 26 to 22 in a decade, student councils and other groups are springing back to life, sports teams are racking up victories and on beautiful spring days, the lawn outside a new classroom building teems with sunbathers and Frisbee throwers -- just like at a typical State U.

Yet the projections worry some educators, who say that these students may not find enough challenges at community colleges -- or enough open seats at four-year schools when they want to transfer.

Others worry that a crush of young, middle-class go-getters could squeeze out the older and lower-income students whose education was the founding mission for community colleges. "It raises real questions about the access to opportunity," said Robert G. Templin Jr., president of Northern Virginia Community College, one of the nation's largest.

Community colleges "used to serve as an opportunity for the less well-prepared or first-generation students," Templin said. If admissions become competitive and budget cuts continue to reduce programs, "maybe they won't have a place now," he added.

The crunch has reached crisis proportions in some parts of the country. Thousands of students hoping to enroll at community colleges in Florida and Washington state were turned away last year after classes filled up early. In California, officials said that about 90,000 students were shut out of community colleges last year, including those who dropped out because they couldn't get into classes and those who arrived too late to enroll.

Some educators have suggested that community colleges could turn to admissions requirements based on grades or SATs. Such a move would violate a long tradition of welcoming anyone who wants an education. But Montgomery College President Charlene R. Nunley argues that a first-come, first-serve policy would be just as punitive to low-income students and working adults, whose busy job schedules or lack of preparation means they are typically the last to register.

"Turning students away from community college is a tragedy," she said. "If they can't come to us, they don't have another higher-education option that's affordable."

Dramatic demographic shifts are nothing new for community colleges. The nation's network of public two-year institutions grew rapidly in the years after World War II to accommodate the wave of veterans seeking degrees through the GI Bill. The system came of age in the 1960s when the baby-boom generation headed off to school, flooding the campuses with young, full-time students.

As the number of high school graduates dropped off in the 1980s and early '90s, community colleges shifted their attention back to adults, focusing on technical training and job skills, often in collaboration with government or local industry. In his recent State of the Union address, President Bush proposed giving community colleges $250 million to bolster such programs. During those same years, the institutions also became known for the remedial education they provided struggling college-bound students.

Now, community colleges are getting a closer look from a kind of student that used to head directly to a four-year school.

For many, the choice still carries the whiff of default. Basit Siddiqui of Columbia turned to Howard Community College after learning that his solid B average and modest record of extracurricular activities no longer made the cut at the University of Maryland Baltimore County, one of many state institutions where the applicant pool has surged in recent years.

"I was surprised," he admitted.

But he was pleased to find at HCC academic rigor comparable to what he expected at a university but with classes a fraction of the size. "My chemistry lab instructor, he wants every number to the decimal," said Siddiqui, who is in his freshman year.

Others followed a more deliberate and calculated path to community college. In her senior year of high school, Michele Jouridine of Columbia applied to a well-regarded art college. Yet she found herself wavering -- would she prefer a nursing career? Ultimately, she decided to wrestle with that decision in a less expensive setting.

"Especially with the prices now" at four-year colleges, "it wouldn't have been good to go and get kicked out. I have friends that happened to," said Jouridine, in her second year at HCC and solidly on the nursing track.

Even while choosing tuition bargains over dorm life, the new crowd of students is doing its best to enjoy the traditional college experience. When President Mary Ellen F. Duncan came to HCC six years ago, she was struck by the number of students clamoring for more campus activities, better fitness facilities and longer library and cafeteria hours. The school now offers a highly competitive honors program and study-abroad opportunities; administrators are even considering opening residence halls.

"From our perspective, it's a plus," Duncan said. "The older students are buoyed by the energy and excitement."

But educators differ on whether community college is the best first step for recent high school graduates. A new study from the U.S. Department of Education presents a surprisingly positive view: Roughly two-thirds of students who complete at least a semester at community college go on to receive a four-year degree, about the same proportion as students who start at a four-year institution.

"It's just as effective a way of getting a bachelor's degree, if you do it the right way," said Education Department analyst Clifford Adelman.

Others remain unconvinced. Calvin W. Lowe, president of Bowie State University, worries about those students who start at community college and never transfer. "For African American students, the best way to get a bachelor's degree is to start at a four-year institution," he said. "Your success in college depends a lot on your surroundings and the ambitions of the people around you."

Occasionally, Podson admits, she finds herself thinking about the things she missed out on by choosing Howard Community College -- "living on campus, having that clique group." For the most part, she's too busy to ponder such things, carrying 13 credits this semester, serving as student government secretary, working part time at the school's information desk.

"There's always something going on," she said. "It's college -- you just don't live here."