College applicants are highly sensitive to small changes to the costs incurred in the application process. The Common Application (CA) reduces the non-monetary costs of additional applications by allowing students to send the same application to any member school with the click of a button. Using survey data from the National Center for Education Statistics and administrative ACT microdata, I show that appliers induced to using the CA by membership changes in local public universities send 1.4 additional applications (a 39% increase) and 2.3 additional ACT score reports (a 47% increase). CA usage has no effect on the probability of enrolling in any four-year institution but increases the probability of enrolling in a CA member school by 15 percentage points. The effects of CA usage are strongest for low-income appliers, who send 2.3 additional applications and enroll in private schools and out-of-state schools at higher rates. Further estimates, while imprecise, suggest that induced CA users are more likely to enroll in more selective, higher-quality schools. The estimated changes in enrollment decisions are too large to be explained solely by small decreases in the time costs of additional applications. College-going students' enrollment decisions are sensitive to changes in application methods for behavioral reasons. Applicants are oversensitive to small, short-run costs relative to the long-run investment of college attendance and lack information about costs of attendance. Centralized application systems that lower application costs may be beneficial because applicants respond by expanding their college search, and universities are able to provide information directly through acceptance letters.