The Journal of American College Health surveyed health center officials at 358 institutions in the United States and Guam.
University health providers were asked about the availability of ECPs, benefits and barriers of the contraceptive and publicity and promotion of the pills.
The study found that many factors influenced whether the pills were available -- including lack of staff, administration objections, legal concerns, religious issues and the desire not to undermine students' use of traditional contraception.
Emergency contraceptives are more commonly known as "morning-after pills" because they are taken the morning after, or within 72 hours of, unprotected sex.
Plan B, a commonly used ECP, prevents pregnancy by using the emission of certain hormones to temporarily stop the release of an egg from a woman's ovary, thereby preventing fertilization.
Though the survey results showed that institutions in the Northeast were more likely to offer ECPs than schools in the Midwest or South, officials at student health centers at UNC, Duke University and the University of California-Berkeley said the pills are available for full-time students.
But each school distributes the pill differently.
Patsy Huff, UNC Student Health Service pharmacy director, said students can get the pill on a walk-in basis at Student Health.
UNC does allow students to get one dose of the contraceptive to have on hand for future use, although it is not intended for frequent use.