The Investing in Innovation (i3) program is the flagship "tiered-evidence" grant program within the federal government, linking grant funding in core education reform areas to rigorous evidence of effectiveness. Its core innovation — smaller grants for projects that are innovative but have less evidence and larger grants to scale up proven approaches — is a model for other federal departments and could significantly improve the results produced by the federal government. The central component of i3, and how it addresses the twin challenges of too few proven effective interventions in education and multiple barriers for even effective interventions to spread substantially, is its three-tier, evidence-based structure. That structure links the funding amount that an applicant can receive to the rigor of the evidence that an applicant provides to support the proposed practice or strategy. Applicants that present only a little evidence can receive small grants (up to $3 million) that support the development and initial evaluation of promising practices, while applicants that present the most rigorous evidence, often large randomized controlled trials, can receive large grants (up to $20 million) that support nation-wide expansion. Since 2010, the program has received over 4,000 applications, and has awarded 157 grants and over $1.3 billion, matched by more than $200 million in private-sector matching funds, to schools and nonprofit partners working in all 50 states. The focus on rigorous evaluation, and the incentives for generating such evidence, has had an impact in education and beyond. Some grantees are already using the evidence generated from their i3 evaluations to move up the tiers and apply for larger grants, and other federal programs are using i3's evidence framework, including the Social Innovation Fund and a major community college grant program at the Department of Labor.