Abstract (Overall) The mission of the Rat Resource and Research Center (RRRC) is to provide biomedical investigators with the rat models, embryonic stem cells, related reagents, protocols, information, support and services that will facilitate their research. The RRRC serves as a unique repository by importing, storing and distributing a large number of rat strains/stocks. It assures that valuable models are preserved and made available to interested investigators, allows researchers to satisfy NIH requirements for resource sharing, relieves individual investigators from the burden of animal distribution and ensures that models are maintained with rigorous genetic quality control and health monitoring to promote experimental rigor and reproducibility. Recent advances in genome editing technologies are facilitating the ability to perform sophisticated genetic modifications in rats in order to study both normal biological processes and disease states. As a result, the number of rat models and the number of investigators using rat models for biomedical research is increasing and the RRRC, as one of the only centralized repositories in the world will continue to serve a critical role for archiving and distributing these new models. To improve repository functions, applied research to optimize methods for sperm cryopreservation and in vitro fertilization in the rat will be undertaken and ongoing efforts to refine, generate and characterize new genetically modified rat models needed by the research community will be performed. To expand the broad utility of the RRRC, we will continue to serve as consultants to the community and we will increase our fee-for-services in the areas of model generation, model characterization, colony management, cryopreservation and rederivation. By providing accessible expertise to investigators working with rats and by expanding our available materials and services, the RRRC will continue to serve as a much-needed “one stop” resource for investigators using rats in biomedical research.