Only 60 percent of students in post-secondary education in the United States graduate within six years of enrollment. Some minority and disadvantaged students graduate at significantly lower rates. As Congress considers reauthorizing the Higher Education Act, some consideration is being given to promoting greater use of evidence-based programs and practices to address these gaps. One option is to create a tiered evidence grant program to support the development, validation, and scaling of evidence-based interventions. Congress has already shown an interest in this approach, with the House Education and the Workforce Committee choosing to include a tiered evidence program, called Impact Grants, in its reauthorization bill earlier this year. A tiered evidence grant program could help address existing college completion disparities for the following reasons: (1) Existing College Completion Rates Are Too Low: The overall college graduation rate is too low and even lower for disadvantaged students. The federal government currently spends over $26 billion per year for Pell Grants for low-income students, but approximately half of these students fail to graduate. The broader economy also suffers as these students fail to become prepared for higher-wage jobs; (2) Evidence-based Strategies Can Improve Educational Outcomes: Researchers have begun to identify evidence-based interventions -- including remedial instructional reforms, academic counseling and mentoring, and comprehensive supports -- that have been shown to increase graduation rates; (3) More Evidence Is Needed of What Works: Most of the existing research on post-secondary interventions is still preliminary. Few interventions are backed by strong evidence of effectiveness. Funding for further research is small, particularly when compared to the billions of dollars spent annually on financial aid and direct assistance to colleges and universities; and (4) Tiered Evidence Grants are a Cost-effective Evidence Building Strategy: Tiered evidence grants, which have been used successfully in other program areas such as K-12 education, are a promising strategy. Because they can be created within existing grant programs, they can build the evidence base at little or no extra cost to the federal government. This paper reviews the potential benefits of a federal tiered evidence grant program in higher education. It includes a review of the existing evidence and draws on lessons learned from other tiered evidence grant programs that could help improve its design.