The purpose of this study is to test whether race is associated with longitudinal success in glycemic control or consecutive years of A1c testing. A retrospective cohort study of 531,995 adults with type 2 diabetes who received care between 20 and 2018 was conducted. The independent variable was race (white, black, Hispanics, and other) . Dependent variables were (1) success rate for glycemic control (A1c <7 [<65 y/o] or <8 [>=65 y/o]) , defined as (number of A1c tests meeting target) / (number of A1c tests) ; and (2) the number of three consecutive years of A1c testing. Confounder variables were age, gender, first year, last year, and health service utilization (yearly rate of outpatient, emergency department, hospitalization and home care visits) . We used generalized linear regression (GLM) to analyze the success rate of glycemic control, and GLM with negative binomial to analyze the number of years of A1c testing. Ten-year level observations (N=531,995) summarized from 3,044,247 year-level electronic medical-record observations showed mean observed years of 5.2, median years of A1c tested of 3.5, and mean fraction of years tested A1c over observed of 69%. Mean success rate of glycemic control was 67% in a 10-year period (IQR of 67%) . The success rate of glycemic control differed by race (P<0.001) : estimates were lower for black (-0.037) , other (-0.066) , and Hispanics (-0.089) compared to white. Controlled for confounders, black had 4% lower success rate of glycemic control than white. The number of three consecutive years of A1c testing differed by race (P<0.001) : estimates were lower for black (-0.100) and other (-0.146) , compared to white. Controlled for covariate plus the success rate for glycemic control, blacks had mean count ratio = 0.9 in the number of 3 consecutive years of A1c testing. Ten-year longitudinal glycemic control was worse among black adults with type 2 diabetes. Greater understanding of the disparities in glycemic control and long-term monitoring of A1c testing is needed. Disclosure H.N.Fu: None. T.Schleyer: None. J.Wolfson: None. T.S.Hannon: Advisory Panel; Eli Lilly and Company. P.Balius: None. M.Weiner: Stock/Shareholder; AbbVie Inc., Accuray, Inc., Allscripts Healthcare Solutions, Amgen Inc., Boston Scientific Corporation, Bristol-Myers Squibb Company, Crispr Therapeutics Ag Com, Express Scripts Hdlg Co, General Electric Co., Globus Med, Inc., IBM, Integer Hldgs Corp Com, Integra Lifesciences Holdings Corp, Johnson & Johnson, Mallinckrodt PLC, Mead Johnson & Company, LLC., Medtronic, Metlife Inc Com, Mylan N.V., Novo Nordisk A/S, Nuvasive, Inc., Orthofix Medical Inc., Perspecta Inc Com, Pfizer Inc., Resmed, Inc., Roche Pharmaceuticals, Seaspine Hldgs, Inc., Senseonics, Stryker Corp., Teva Pharmaceutical Industries Ltd., Varex Imaging Corp., Varian Med Sys, Inc., Walgreens Boots Alliance, Inc. Funding T15LM012502, UL1TR002529, the Lilly Endowment Physician Scientist Initiative