The conduct of clinical research is a resource-intensive endeavor typically funded by the federal government, philanthropies, or manufacturing industry. Trailists who seek funding must reliably estimate the cost to conduct the research (Box). Although budgets seem mundane, financial backing requires an accounting of how the funds will be used to accomplish the stated objectives. Grant applications must offer a sound scientific rationale for the research, ensure the ethical treatment of the participants, and construct a realistic budget that justifies the investment. Herein, we review considerations for preparing the budget.¹ Key determinants to the size of the budget include sample size, the need to render nonroutine clinical care, the overall timeline of the proposed work, and the number of sites participating in a trial. As each of these grows, so grows the number of research personnel and the overall budget. This review enumerates the different types of available funding² and summarizes the way to apply for such funds, using the United States as an example. The budget and funding request are central to the planning of a serious research endeavor.