The focus of this report is on current university efforts and recommended future improvements to prepare PhD and master’s students for a fuller range of careers comprising the advanced STEM workforce. The report includes findings from a two-year CGS project (2014-2016), funded by a grant from the National Science Foundation (NSF #1413827), to map the landscape of professional development programming at US universities for graduate students in science, technology, engineering, and mathematics (STEM) and to identify opportunities to enhance professional development of STEM graduate students, nationally. This project identified promising practices, common challenges, recommendations, and possible next steps toward coordinated improvements to the professional development of STEM graduate students, including PhDs, master’s, and postdoctorates. To advance this goal, we probed answers to a number of questions, such as: How prevalent are formal graduate student professional development programs? Who needs to be involved in developing and delivering these programs? What skills do these programs address, and what skills are missing or underemphasized? Are graduate students participating in these programs? Do faculty support student participation in these programs? What are the biggest challenges facing student engagement in and faculty support for these programs? How do we know this programming is effective? And, what steps do recent graduates, employers, and university leaders think should be taken to improve professional development for graduate students? We sought answers to these questions through three means: 1) a survey of graduate deans, STEM faculty, and staff responsible for professional development programming; 2) in-depth interviews with 10 chief research officers or other senior leaders at organizations from different sectors of the advanced STEM workforce responsible for supervising and hiring STEM PhDs and master’s recipients; and 3) a workshop convened in fall 2015 of national experts, employers from multiple sectors of the advanced STEM workforce, federal funders, graduate deans, and recent PhDs to advance the conversation about challenges and promising solutions and models. While the focus of this project was on formal university professional development programs for graduate students, examples of other types of professional development programs and experiences were frequently cited, ranging from large-scale federal fellowship and internship programs to particular university-industry partnerships. These, as well as the recommendations for stakeholders beyond universities, will be noted throughout the report. While postdoctoral training was not an explicit focus of this project, many of the programs described here serve postdoctoral fellows as well as PhD candidates and master’s students.The report includes discussion of useful tools and resources, as well as of issues that commonly arise in university discussion around professional development. Examples of such issues include: whether this training should be integral or supplemental to the education received in one’s discipline or degree program; how to prepare a diverse group of students for the wide range of STEM- and STEM-related careers and whether this should even be a part of the mission of graduate degree programs in research fields; and whether the emphasis of professional development efforts should be on generic skills, STEM-specific skills, or professional formation, more broadly. As part of this project, CGS identified a large number and wide variety of US university professional development programs for graduate students. An online compendium of these programs is included both as an appendix to the electronic version of this report and in an interactive online format to inform program improvements. The compendium is intended for senior university leaders seeking a reference point for their efforts to develop or enhance existing programs.