People with type 1 diabetes (PWD) that strive for lower glucose targets are in need of more precise dosing and may require smaller insulin dose adjustments. Most currently available pens deliver insulin in one unit (U) increments, and few deliver half (0.5) U. There is a need to better understand who is using half unit pens (HUP) and their potential benefit for patients in the real world. This study aims to characterize PWD who have used (current/former=EVER users) HUP vs. those PWD that have never used HUP (NEVER users). This research also identified the main factors driving benefit from PWD perspective. An observational, cross-sectional survey was completed through T1D Exchange’s online patient community, myGlu.org. Chi square test, Fisher’s exact test, and t-tests were used for analyses. A total of 278 PWD (156 EVER, 122 NEVER users) over the age of 18 were recruited for the study (mean age: 42±13 years old, gender: 55% male, mean BMI (kg/m2): 26.0 ±3.8, and mean A1c (%): 6.3± 0.9), EVER users had diabetes a shorter duration (p Disclosure C. Piras de Oliveira: Employee; Self; Eli Lilly and Company. Stock/Shareholder; Self; Eli Lilly and Company. B. Mitchell: Stock/Shareholder; Spouse/Partner; Eli Lilly and Company. L. Fan: Employee; Self; Eli Lilly and Company. C. Garey: None. B. Liao: Employee; Self; Eli Lilly and Company. J. Bispham: None. N. Vint: Employee; Self; Eli Lilly and Company. M. Perez-Nieves: Employee; Self; Eli Lilly and Company. Stock/Shareholder; Self; Eli Lilly and Company. A.H. McAuliffe-Fogarty: Advisory Panel; Self; Novo Nordisk Inc..