DEVELOPMENT CORE: SUMMARY In the Development Core (DC), our main objectives are to engage and support early-career population scientists and launch innovative research projects by interdisciplinary teams. The services of the Core will maximize the scientific impact of our affiliates by catalyzing the design, creation, and analysis of new data to advance population science, increasing all Population Studies Center (PSC) scientists’ productivity, innovation, and competitiveness for external funding. The Core’s activities will harness the significant resources available at our Center, the Institute for Social Research (ISR), and the University of Michigan (U-M) to enhance the reach of P2C funding. We will continue to offer activities tested over the past funding period: (1) pilot small grants; (2) intensive mentoring; and (3) experienced peer review. Careful assessment have led us to propose several important changes and additions for the next five years. First, we propose a new leadership structure that eliminates Associate Directors in favor of a five faculty member Scientific Advisory Committee (DC-SAC) representing our strengths in innovative, large-scale surveys; cutting-edge data science work using “organic” data from administrative records and other sources; and pioneering work with experimental designs and interventions, along with special expertise in the study of population health disparities and population genetics. Second, we will add: (1) an ongoing program of DC consulting services, with initial consultation and “triage” from the DC lead and research administrator, and follow through from appropriate scientists on our DC-SAC, the STC, or the AC; (2) an annual series of DC workshops to demystify NIH proposal components and the application process; (3) a new plan for ongoing access to senior peer review of draft proposals; and (4) a more structured use of key data collection projects in each PRA to provide examples and learning opportunities to our new investigators and to maintain a strong connection between existing projects in each PRA and innovative plans for new projects by affiliates. All of these resources and services will prioritize junior scientists. Third, we will begin to make DC resources available to population scientists at institutions that are not funded by the NICHD Population Dynamics P2C Program. To outreach to early career scientists interested in pursuing population dynamics research, we will harness ISR’s networks of non-U-M scientists connected through: (1) multi-institution data creation projects; (2) ISR Summer Institute instructional programs; and (3) our family of R25 educational programs. These coordinated, intensive resources for U-M affiliates and those at institutions without PDB infrastructure funding would not be available in the absence of continued P2C funding.