OBJECTIVES:  Injectable glucagon was approved in the United States in 1998 for the treatment of severe hypoglycemia in patients with diabetes mellitus (DM) and as a diagnostic aid in gastrointestinal radiologic examinations. This study describes the patterns of glucagon utilization in patients with DM who initiated insulin therapy in the United States. METHODS:  Patients with DM (ICD-9-CM 250*) who initiated insulin therapy between 2004 and 2012 in Truven Health MarketScan® database were included in the study. The extent of injectable glucagon use was measured during 12 months after insulin initiation date (index date) stratified by severe hypoglycemia events that occurred any time after the index date. Severe hypoglycemia was defined as hypoglycemia events that required hospitalization or emergency room visit. Duration of glucagon use was determined by the number of days between prescription initiation and end of day supply. RESULTS:  A total of 1,487,601 patients with DM started insulin therapy (median age 61 years, 51% females). Among them, 1.6% (n=23,191) started injectable glucagon therapy. The vast majority of glucagon users continued therapy for a median of 3 days (49% females). Among 89,059 insulin initiators with severe hypoglycemia (mean age 63 years, 56% females), only 1.7% (n=1,510) started glucagon injection. The median duration of glucagon use among those with severe hypoglycemia was 2.7 days (52% females). CONCLUSIONS:  Utilization of injectable glucagon among insulin-treated patients who experienced severe hypoglycemia appears to be low. More research is needed to explore factors determining utilization patterns in this group of patients with DM.