Abstract The appetite for cutting-edge cancer research, across medical institutions, scientific researchers, and health care providers, is increasing based on the promise of true breakthroughs and cures with new therapeutics available for investigation. At the same time, the barriers for advancing clinical research are impacting how quickly drug development efforts are conducted. For example, we know now that under a microscope, patients with the same type of cancer and histology might look the same; however, the reality is that most cancers are driven by genomic, transcriptional, and epigenetic changes that make each patient unique. Additionally, the immunologic reaction to different tumor types is distinct among patients. The challenge for researchers developing new therapies today is vastly different than it was in the era of cytotoxics. Today, we must identify a sufficient number of patients harboring a rare mutation or other characteristic and match this to the right therapeutic option. This summary provides a guide to help inform the scientific cancer community about the benefits and challenges of conducting umbrella or basket trials (master trials), and to create a roadmap to help make this new and evolving form of clinical trial design as effective as possible.