Community Health Institute/JSI (CHI/JSI) is working with the Health Resources and Services Administration (HRSA) to revise and consolidate the rules by which federal shortage area designations are evaluated (including Health Professional Shortage Areas (HPSAs), Medically Underserved Areas (MUAs), and Medically Underserved Populations (MUPs)). These designations have become the foundation upon which nearly every component of the federal health care safety net system now rests. As such, changes to these rules are of intense interest to all stakeholders in the federal safety net system. CHI/JSI, working with the Bureau of Health Professions and a panel of national experts in health care access, will craft revisions to the current rules. CHI/JSI is responsible for conducting extensive analysis in support of the factors being considered for inclusion, and ultimately for evaluating the likely impact of the changes on the existing safety net infrastructure nationwide.