Of adults with type 2 diabetes, 84% take antihyperglycemic medication. Successful treatment requires active monitoring and medication dose adjustment by health providers. The objective of this study was to determine how a mobile-phone-based coaching system for diabetes management influences physician prescribing behavior. This secondary data analysis is based on a cluster randomized clinical trial that reported patients provided with mobile self-management had reduction in glycated hemoglobin (HbA1c) of 1.9% over 1 year, compared to 0.7% in control patients (P < .001). Participants were primary care patients with type 2 diabetes randomized at physician practice level into a control group (n = 55) and intervention group (n = 62). Main study measures were patients’ medication records (medication, dose, frequency, start and end date) abstracted at baseline and study end. Antihyperglycemic medications, including sulfonylureas or thiazolidinediones, and antihypertensive and antilipemic medications were analyzed. A higher percentage of patients in the intervention group had modification and intensification of incretin mimetics during the 1-year study period (9.7% vs 0.0% and 8.1% vs 0.0%, both P = .008). A higher percentage of patients in the intervention group had modification and intensification of metformin (24.2% vs 7.3%, P = .033). The overall difference in physician prescribing of oral antihyperglycemic medications was not statistically significant. Our results suggest mobile diabetes interventions can encourage physicians to modify and intensify antihyperglycemic medications in patients with type 2 diabetes. Differences in physician prescribing behavior were modest, and do not appear to be large enough to explain a 1.2% decrease in HbA1c.