Background: Self-care of individuals with type 1 diabetes (T1D) may play a significant role in development and treatment of impaired awareness of hypoglycemia (IAH). This dissertation aimed to identify and define characteristics of self-care clusters in adults with T1D, explore the interrelationships between attitudes, self-care, and IAH within clusters qualitatively, and integrate findings to develop a typology. Methods: Adults (n=200, 27% Black, 61% female) with T1D (mean(SD) age: 39(15) years, T1D duration: 22(14) years) reported personal, clinical and social determinants of health, glycemic attitudes and self-care (Self-Care of Diabetes Inventory; 3 self-care scales: maintenance, monitoring, management; 1 confidence scale; scored 0-100; scores ≥ 70 are adequate). Cluster analysis via Ward’s method was performed with self-care domains as criteria. Semi-structured qualitative interviews were performed and analyzed via directed content analysis. An integrated results matrix was employed to develop a typology of self-care in T1D. Results: A typology of three self-care types was found: Expert (n= 70, 70% White, 20% IAH, insulin pump use: 63%, mean(SD) age: 45 (17) years, T1D: 25 (16) years), Inconsistent (n= 112, 75% White, 30.4% IAH, Insulin Pump use: 75%, mean(SD) age: 37 (14) years, T1D: 21 (13) years), and Novice (n= 18, 39% White, 27.8% IAH, Insulin pump use: 44%, mean(SD) age: 27 (7) years, T1D: 16 (8) years. Expert was characterized by adequate self-care across domains (Mean (SD) maintenance: 84.9 (8.8), monitoring: 85.0 (8.8), management: 72.5 (10.0). Inconsistent was characterized by adequate maintenance (78.6 (8.9), and inadequate monitoring (65.6 (9.77)) and management (56.8 (10.1)). Novice was characterized by inadequate self-care across domains (maintenance: 51.9 (7.7), monitoring: 56.9 (12.9), management: 44.5 (6.3)). Types differed across age (p<.001), race (p<.01), insulin pump use (p<.05), Self-Care Maintenance (p<.001), Monitoring (p<.001), and Management (p<.001). No differences were found in IAH or T1D duration. Conclusions: This self-care typology may explain in-part heterogeneity in T1D outcomes such as IAH. Therefore, understanding a patient’s self-care type may offer a more individualized approach for more effective treatment of IAH.