Before the Affordable Care Act expansion in 2014, Medicaid program primarily covered pregnant women, low-income families with children, and elderly and disabled people with Supplemental Security Income (SSI). The expansion extended coverage to most of the adults up to 138% Federal Poverty Level (FPL), and it was adopted by 27 states in 2014 and by 2021, it increased to 39 states (including DC). Past literature provided evidence that this led to a significant increase in the total Medicaid coverage and consequently a decrease in the total number of the uninsured individuals in the expansion states. According to CDC, among chronic conditions, Diabetes is one of the leading causes of morbidity and mortality in the US. Access to health care is most essential to stay healthy for a diabetic person. With high cost of supplies, medication, education, and medical care to manage diabetes, affordable and adequate health insurance is imperative. This paper examines the impact of the Affordable Care Act (ACA) Medicaid Expansion on diabetes diagnoses, and its management to prevent health complications caused by diabetes. Employing a difference-in-differences framework, we exploit the variation in the eligibility caused by the ACA expansion to compare the changes in diabetes outcomes in the expansion states (treatment group) with the non-expansion states (control group).