Certain antihyperglycemic therapies modify cardiovascular and kidney outcomes among patients with type 2 diabetes, but early uptake in practice appears restricted to particular demographics. We examine the association of Medicaid expansion with use of and expenditures related to antihyperglycemic therapies among Medicaid beneficiaries.We employed a difference-in-difference design to analyze the association of Medicaid expansion on prescription of noninsulin antihyperglycemic therapies. We used 2012-2017 National and State Medicaid data to compare prescription claims and costs between states that did (n = 25) and did not expand (n = 26) Medicaid by January 2014.Following Medicaid expansion in 2014, average noninsulin antihyperglycemic therapies per state/1,000 enrollees increased by 4.2%/quarter in expansion states and 1.6%/quarter in nonexpansion states. For sodium-glucose cotransporter 2 inhibitors (SGLT2i) and glucagon-like peptide 1 receptor agonists (GLP-1RA), quarterly growth rates per 1,000 enrollees were 125.3% and 20.7% for expansion states and 87.6% and 16.0% for nonexpansion states, respectively. Expansion states had faster utilization of SGLT2i and GLP-1RA than nonexpansion states. Difference-in-difference estimates for change in volume of prescriptions after Medicaid expansion between expansion versus nonexpansion states was 1.68 (95% CI 1.09-2.26; P < 0.001) for all noninsulin therapies, 0.125 (-0.003 to 0.25; P = 0.056) for SGLT2i, and 0.12 (0.055-0.18; P < 0.001) for GLP-1RA.Use of noninsulin antihyperglycemic therapies, including SGLT2i and GLP-1RA, increased among low-income adults in both Medicaid expansion and nonexpansion states, with a significantly greater increase in overall use and in GLP-1RA use in expansion states. Future evaluation of the population-level health impact of expanded access to these therapies is needed.