Identifying the best set of colleges to which to apply is not a simple task. The importance of any one application depends on the likely outcomes of other applications, and this logic and information is difficult to grasp for anyone, let alone high school students. To simplify this task, the College Board recommends that students submit a total of four to eight applications to a combination of "reach," "match," and "safety" schools. However, many academically well-qualified students do not follow this advice, primarily by selecting too many "safety" schools relative to "reach" and "match" schools. Students who do not follow the College Board's guidelines for creating a college list limit their postsecondary options, in some cases dramatically so. At one extreme, students who do not apply to a four-year college at all completely limit their choice set. Similarly, well-qualified students who only apply to less/nonselective colleges consign themselves to institutions with relatively few resources, low graduation rates, and academically weaker college peers. Low income students typically underapply with regard to both the quantity and quality of college applications compared to higher-income students with similar academic qualifications. Thus, the choice of college application portfolio likely serves as an important mechanism that differentiates the college choices of low-income students from those of others. Provided in this research brief is a discussion of application barriers students may encounter which may be procedural, geographical, cultural, informational, or financial. Potential solutions to reduce and remove these barriers include programs that substantially alter the usual application processes, provide information about and support outreach by colleges, promote the use of college application fee waivers, and improve college counseling. Another natural approach to favorably influencing the college application choices of students is to provide them with additional college counseling designed to overcome informational and procedural barriers. [This work is the product of a series of collaborations between the College Board and the Center for Education Policy Research at Harvard University.]