Background: Evidence from large randomized clinical trials supports the benefit of SGLT2is to improve cardiovascular and kidney outcomes in patients with type 2 diabetes mellitus (T2DM). In light of this evidence, prescription patterns of SGLT2i among US Medicare beneficiaries were evaluated. Methods: Antihyperglycemic medication prescribers were based on metformin prescribing in national Medicare part D prescriber data. The proportion of clinicians prescribing SGLT2i was assessed overall and across specialties in 2018, with changes assessed from 2014 to 2018. The relative use of SGLT2i was compared with other second-line antihyperglycemic medication classes, sulfonylureas and dipeptidyl peptidase-4 inhibitors (DPP4is), without known CV benefits. Results: Among the 232,523 unique clinicians who prescribed metformin for Medicare beneficiaries in 2018, 45,255 (19.5%) prescribed SGLT2i - varying from 72% of endocrinologists to 14% of cardiologists. Among clinicians who prescribed both sulfonylureas and SGLT2i, SGLT2i were prescribed to 33% (IQR 18%, 67%) the number prescribed sulfonylureas. Of 118,091 metformin-prescribing clinicians who also prescribed DPP4i, 39,511 (33.5%) used SGLT2i, with a median 50% SGLT2i prescription volume relative to DPP4i (IQR 33, 100). Between 2014-2018, the number of unique clinicians prescribing SGLT2i increased from 5-fold, from 9,048 in 2014 to 45,255 in 2018, and proportionate utilization of SGLT2i per prescriber relative to sulfonylureas also increased from 19% in 2014 to 33% in 2018 (P-trend <0.001). Conclusions: A vast majority of diabetes-treating clinicians did not prescribe SGLT2i to Medicare beneficiaries as recently as 2018. Moreover, prescriptions of sulfonylureas and DPP4is, which have no known cardiac or kidney benefits, were 3 and 2 times more frequent, respectively, than those of SGLT2is. These findings highlight opportunities to improve care and outcomes for patients with T2DM.