Eating Disorder-Diabetes Mellitus Type 1 (ED-DMT1) refers to individuals who have type 1 diabetes and a co-occurring eating disorder. The aim of this study was to identify current treatment practices for individuals with ED-DMT1 in a residential eating disorder treatment setting. Clinical nutrition managers (CNMs) at 18 residential eating disorder treatment facilities were interviewed about treatment practices for patients with type 1 diabetes. Four themes were identified through qualitative case study analysis: 1) nutrition interventions for patients with diabetes, 2) medical diabetes management, 3) interdisciplinary diabetes team, and 4) CNM's assessment of diabetes care. The majority of CNMs interviewed reported utilizing an exchange- based meal plan, which is well suited for patients with type 1 diabetes. Dietitians described the use of diabetes technology (e.g., insulin pumps and continuous glucose monitors) and described a gradual advancement of responsibility and autonomy with portioning food at meals and snacks and managing diabetes care. The dietitian is heavily involved in providing diabetes education along with the medical and/or nursing team. The majority of CNMs interviewed demonstrated knowledge deficits related to diabetes management and expressed the need and desire for increased education for themselves and other staff members in order to provide the highest quality of care.