This R01 responds to PAS-20-160 (Small R01s for Clinical Trials Targeting Diseases within the Mission of NIDDK). Our objective is to test the feasibility, acceptability, and initial efficacy of using behavioral economics incentives (BEI) in a novel, semi-automated intervention to target daily insulin BOLUS scores in adolescents with suboptimal insulin use. There is a critical need for efficacious and easy to implement interventions targeting self-management behaviors in adolescents with type 1 diabetes (T1D). This is because national registry data suggest that only between 15-28% of adolescents achieve their glycated hemoglobin (HbA1c) target, thereby placing the majority of them at increased risk for serious acute and long-term complications. BEI interventions are efficacious for promoting health behaviors including frequency of self-monitoring blood glucose (SMBG) in youth. Moreover, there is evidence that BEI can be relatively easy to implement, especially when using Non-Contingent BEI. But with the uptake of integrated insulin pump and continuous glucose monitor (CGM) systems and the new FDA approval enabling youth to dose for insulin based solely on CGM, we believe the long-term value of targeting SMBG alone in BEI interventions is limited and that daily insulin use is the next logical self-management target. Building off of our prior work, the insulin BOLUS score offers a specific, measurable, and valid treatment target for daily insulin use that is also more closely related to HbA1c than SMBG or Total insulin boluses per day. Thus our Aims are: 1) examine the feasibility and acceptability of our semi-automated BEI intervention (called Coin2Dose) that targets daily BOLUS scores in adolescents and 2) examine the preliminary efficacy of Coin2Dose versus a standard care control (SC) group on youth daily BOLUS scores, HbA1c, and glucose time in range (TIR). We also include an exploratory aim to examine the incremental impact of using Contingent versus Non-Contingent BEI within our Coin2Dose intervention on youth's BOLUS scores, HbA1c, and TIR. Coin2Dose will deliver automated text messages to cue adolescents to bolus for insulin, plus BEI for daily BOLUS activity. To enhance the scientific rigor of this R01, we will use the ORBIT Model for behavioral intervention development. Consistent with this model, we will recruit 180 adolescents and a parent to participate in 1- a telehealth focus group (ORBIT Phase 1a: Define; n= 20), 2- a formative pre-test (ORBIT Phase 1b: Refine; n=10), or 3- a pilot randomized clinical trial (ORBIT Phase 2: RCT Pilot; n=150). Our RCT Pilot will randomize teens with suboptimal insulin use (BOLUS score \<2.5; 70% of teens based on pilot data) to a SC or 1 of 2 versions of Coin2Dose that only differ based on our use of personalized (Contingent) v. non-personalized (Non-Contingent) BEI. Adolescents will participate in 12-weeks of active treatment, plus a 12-week follow-up period. This small R01 is Significant for its potential to yield: 1- preliminary data supporting our new BEI intervention targeting daily BOLUS scores, which may also improve youth HbA1c, 2- novel data exploring the incremental impact of Contingent v. Non-Contingent BEI, which has implications for Coin2Dose as well as the broader uptake of BEI interventions.