This is a new era in astronomy and astrophysics on every measurable axis, where fundamental breakthroughs are being made with astonishing frequency. The entire Universe is our laboratory, and analysis of these data has transformed our understanding of our place in the cosmos. Despite these strides, one of the greatest challenges to the astronomical community has been building environments where people with historically marginalized identities can thrive. This critically limits the pool of innovative minds who may gain exclusive access to cutting edge research and thus, who can shape the future of the field through transformative science, mentoring and professional leadership. The overarching goal of the Lamat Institute has been to invigorate the field through training and workplaces that reflect equity-advancing values and allow the full human diversity of our nation to meaningfully and maximally contribute to the field. Cultivating equitable access has allowed the program to dramatically increase equitable participation. In this talk, I will first offer an introduction to Lamat's mentoring philosophy and design principles and discuss the ability of REU programs to facilitate long-term student success.