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Getting into a dream college can be a tough task, particularly if it receives an abundance of applications. Some schools are highly exclusive, accepting only a small percentage of applicants. Among the most selective colleges ranked by U.S. News, the fall 2018 acceptance rates range from 4% to 8% at these 13 institutions, including ties.

While applicants to these 13 schools face long-shot odds for acceptance, that isn't true at the majority of schools across the U.S. In fact, the national average acceptance rate at the 1,363 ranked schools that provided acceptance rate data to U.S. News was 67% in fall 2018. Broken down, that means two out of three students were accepted last year at schools to which they applied.

The most selective schools, however, accept only small proportions of applicants. Stanford University in California, the college with the lowest reported acceptance rate among ranked schools, only took in 4% of applicants in fall 2018.

Selectivity demands high standards. According to U.S. News data, the average SAT score for students admitted to Stanford in fall 2018 was 1420, well above the national average of 1068. Admitted students in the 25th-75th percentile range scored between 720-800 on the math section and 700-770 on the evidence-based reading and writing portion. The national average scores on those sections are 531 and 536, respectively, according to the College Board, which administers the test.

U.S. News data also shows that freshman students admitted to Stanford who submitted their high school GPA had an average 3.9 GPA, and 96% of those who submitted their high school class standing were in the top 10% of their class.

Right behind Stanford are Harvard University in Massachusetts and Princeton University in New Jersey, both of which had a 5% acceptance rate for fall 2018 applicants. Across all 13 of these schools, the average acceptance rate was a mere 7%.

Of the colleges on this list, six are Ivy League schools. Looking at other factors, these 13 colleges range in size, location and by institutional category. There are 11 National Universities represented here, defined as institutions that are often research-oriented and offer bachelor's, master's and doctoral degrees.

Also on this list is one National Liberal Arts College, a type of school that emphasizes undergraduate education and awards half or more of its degrees across liberal arts fields. Likewise, one Regional College appears here, a type of school that focuses on undergraduate education but grants less than half of its degrees in liberal arts fields.

Students interested in attending a highly selective school should understand the admissions standards, recognize the competitive nature of getting in and familiarize themselves with how colleges choose students to admit.

Below is a list of the 13 colleges where it was most difficult to gain acceptance in fall 2018. Unranked schools, which did not meet certain criteria required by U.S. News to be numerically ranked, were not considered for this report.

Don't see your school in the top 13? Access the U.S. News College Compass to find acceptance rates, complete rankings and much more. Sign up for the U.S. News Extra Help: College Admissions free email newsletter to receive expert advice twice a month.