ST. LOUIS — The excitement of acceptance into that dream college has passed. The first day of classes is still weeks away. But the resources provided by high school teachers and computer labs are no longer available for recent graduates.

Education researchers and academic counselors call it “summer melt,” the precarious time when some college-bound students fall through the cracks, at risk of abandoning their higher education plans entirely. Studies show that first-generation college students and those from low-income families are particularly vulnerable.

In St. Louis, a drop-in counseling center helps such students negotiate financial aid agreements, housing contracts and the other many details of college enrollment. School districts in Chicago, Dallas, Miami, Minnesota and West Virginia are among those using text messages to keep aspiring college students on track.

“You get the acceptance letter and start the celebration,” said Shauna Cunningham, a high school guidance counselor who’s spent the past two summers at the St. Louis Graduates High School to College Center. “They don’t realize all the other steps.”

Recent studies by Harvard University’s Center for Education Policy Research found that an estimated 20 percent of graduating seniors from urban school districts abandon their plans to attend college over the summer.

Among prospective community college students, the summer melt rate increases to about 40 percent, said Ben Castleman, assistant professor at the University of Virginia.

A lack of financial aid is to blame in about half of those cases, Castleman said. But students also wind up getting derailed by much less significant hurdles, from failing to meet enrollment deadlines to registering for summer orientation programs.

“The idea was that if you could get a kid to graduate from high school, they’d been accepted and chosen where to go, that student was going to show up,” he said. “What our work shows is that in fact, students encounter a pretty complicated array of financial and procedural tasks to complete” in summer.

Schools are beginning to find that reducing summer melt doesn’t require dramatic intervention. For just $7 per student, school districts in Lawrence and Springfield, Mass., were able to boost their number of college-bound graduates.

Students received introductory text messages. Their parents received similarly tailored messages.