This application is submitted in response to RFA-DK-17-506, “Limited Competition for the Continuation of the Chronic Renal Insufficiency Cohort (CRIC) Clinical Centers (U01),” for the Hopkins/University of Maryland (Hopkins/UMB) Clinical Center. Over Phases 1-3 of CRIC (2002-16), the study enrolled 5,499 adults with chronic kidney disease (CKD) at 7 Clinical Centers to address the overarching goals of identifying risk factors for CKD progression and clarifying the relationship between kidney dysfunction and its consequences, particularly cardiovascular disease and mortality. In Phase 4 of CRIC (aka CRIC 2018-23), the Hopkins/UMB center has the following specific aims: 1. To re-enroll current participants [~415 anticipated (~370 without ESRD, ~45 with ESRD)] 2. To collect exposure and outcome data per the CRIC Phase 4 protocol 3. To maintain high levels of retention in the study 4. To investigate self-reported clinical events and obtain supporting medical records and documentation. 5. To enter data and collect/process/ship biological specimens 6. To implement local quality assurance and quality control procedures as a means to obtain standardized, high quality measurements 7. To monitor data collection, data entry, and follow-up rates 8. To participate in governance and oversight of CRIC through study-wide subcommittees and activities 9. To publish and present findings from the CRIC Study 10. To promote and support the conduct of ancillary studies in CRIC 11. To engage investigators at the Hopkins/UMB investigators to assist in local analysis of CRIC data 12. To engage investigators in the broader scientific community The investigative teams at Hopkins and UMB have vast experience in the design and implementation of rigorously conducted, influential research. During Phases 1 to 3, the Hopkins/UMB Center was a high performing center that exceeded its recruitment goals; achieved high follow-up rates; and collected high quality data. Likewise, center investigators have consistently had prominent leadership roles (e.g. Co-Chairs of Recruitment and Retention, Ancillary Studies, and Publications Executive Subcommittees). In Phase 4, we remain extremely well-positioned to successfully implement the study. On a final note, we remain deeply committed to the success of CRIC and look forward to providing strong scientific leadership in this tremendously important research effort.