The HCHS/SOL Visit 3 (January 15, 2020-January 14, 2024) consists of NHLBI core clinic exam procedures with an enhanced core component funded by NIMHD. Together, these exam components serve as a platform for independently funded exam components via ancillary studies that are consistent with or complementary to HCHS/SOL study objectives. Components of the Visit 3 core clinic exam include: anthropometry, updated participant personal information, personal medical history and focused health interviews, sitting blood pressure, and phlebotomy for selected laboratory tests (total cholesterol, HDL-C, triglycerides, fasting glucose, and HbA1c) and storage of serum/plasma/whole blood and urine samples for future analyses. The enhanced core component comprises a set of 108 questionnaire items across 11 domains. To maximize efficiency and minimize study participant burden for the exam, all components from ancillary studies planned for HCHS/SOL Visit 3 were reviewed for harmonization and integration with the core and enhanced core exam. Eighteen ancillary studies funded by R01 grants are now integrated into the Visit 3 exam. This Field Center supports the HCHS/SOL study participants in Chicago IL.