OBJECTIVES:  To better understand type 2 diabetes (T2D) patients’ experiences with using basal insulin. METHODS:  This was a qualitative focus group study among patients with T2D who were current basal insulin users. The HealthCore Integrated Research Database was used to identify currently-active, commercially-insured, survey-eligible patients based on claims from 1/1/2015-12/31/2015. Patients with Cincinnati and NYC zip codes were invited to participate in 90-minute focus groups conducted by an experienced moderator. Two focus groups (six individuals each) were conducted in Cincinnati and two in NYC. The focus group proceedings were audio and video recorded and transcribed. Patients’ insights regarding basal insulin administration, prescription fill patterns, and overall basal insulin use experiences were grouped into common themes to provide a deeper understanding of the issues surrounding the use of basal insulin. RESULTS:  Of 24 participants, 58% were female, mean age 52.1 years, and mean time since T2D diagnosis 11.9 years. The majority of participants reported that their insulin prescription fills contained more drug than needed and reported having ‘left over’ insulin at the end of their refill period. Nearly everyone reported using the entire amount of insulin in each vial/pen before opening a new one. This led to stockpiling of insulin over time if filled regularly; skipping a refill occasionally if they had enough supply from prior fills to cover the month; or delaying their refill until all medication was used. Missing a dose was considered a rare occurrence and was mainly due to a change in routine or environment. Adjusting their insulin dose within ±5 units was common and typically done in response to a blood sugar reading, healthy/poor eating, exercising, or a general feeling of well-being. CONCLUSIONS:  Insulin filling behaviors are complex and depend on multiple factors. Inconsistent filling patterns may not be a true reflection of their adherence to insulin therapy.