Recent trends regarding GDM medication use have not been well described in prior literature. We identified pregnant patients enrolled in Tennessee Medicaid with a GDM diagnosis who a delivered in 2007 to 2019. We studied initial GDM medication use by delivery year (overall and by medication type). Over twenty percent of patients filled at least one prescription for GDM medication in the study period, with a significantly increasing prescribing trend over time. Starting in 2016, metformin replaced glyburide as the most common medication prescribed, which corresponds temporally with the emergence of evidence on the safety and effectiveness of different oral hypoglycemic medications and related changes in ACOG practice recommendations. These findings highlight how practice patterns have potential to shift quickly in response to evolving data.