Low-income high-achieving students are less likely than high-income peers to enroll in selective colleges. Financial certainty interventions can address administrative burdens that stifle their enrollment, even when colleges are tuition-free for them. However, we do not know whether these interventions are effective when students enjoy admissions certainty (e.g., with percent plans) or how financial certainty interventions interact with automatic admissions. We tested the efficacy of a direct-to-student intervention that proactively guaranteed low-income students free tuition, on-campus housing, and a housing scholarship at the University of Texas at Austin. The intervention increased application rates for the full sample, but only increased enrollment at the university among students eligible for automatic admission, for whom the intervention nearly doubled enrollment (43% vs. 24%).