OBJECTIVES The impact of various medical insurance structures on the quality of care is not clearly understood. Drug utilizations patterns of type 2 diabetes patients may be affected by health care access, which vary across various types of health insurance and may lead to disparities in disease control and clinical results. METHODS A cross-sectional analysis was conducted on data from the National Health and Nutrition Examination Survey (NHANES) 2005 - 2006. Based on data from survey, patients aged 20 years and older with diagnosed type 2 diabetes were classified as patients with commercial insurance, Medicare and/or Medigap, Medicaid, multiple insurance, other types of insurance and no health insurance coverage. Likelihood of oral anti-diabetic medications, insulin or combinations and the likelihood of having successful Glycemic control were modeled with multi-variables logistic regression analyses with adjustment for age, gender, BMI, ethnicity, diabetic complications, household incomes and important co-morbidities. RESULTS A total of 403 diabetic patients were included in the analysis. Compared to commercially-insured patients, patients under Medicare (OR=1.36, 95% CI = 0.62, 3.00) or Medicaid (OR=2.32, 95% CI = 0.76, 7.04) were more likely to be treated with insulin, but less likely to receive oral anti-diabetic medications (OR=0.19, 95% CI = 0.09, 0.40 for Medicare; OR=0.19, 95% CI = 0.07, 0.51 for Medicaid). The likelihood of having successful glucose control varied but was not significantly different across types of plans (P>0.05). CONCLUSIONS Treatment patterns varied across various types of health insurance plans and might have impact on the optimum quality of care and expenditure implications.