In order to better tailor treatment to specific populations, factors which contribute to health disparities among different racial/ethnic groups must be examined. Among Mexican American individuals, the high rate of diabetes represents a significant contributor to overall health. The present study focuses on factors affecting diabetes status among Mexican Americans born in either Mexico or the United States using the 2007 – 2008 NHANES data set. Comparisons were made between diabetes status based on self-report and clinical classification using HbA1c. Results indicated that within the diabetic subsample, Mexican Americans born in Mexico were twice as likely to be incorrectly classified as non-diabetic, when they actually were diabetic, when using a self-report method. In contrast, nativity did not result in differences in diabetes incidence using the HbA1c clinical cut-score diagnostic classification. Age, BMI, gender, nativity, and health insurance coverage were found to have varying relationships to diabetes prevalence and HbA1c levels, but time in the U.S. for Mexico-born individuals was not found to uniquely predict diabetes incidence. Analyses also demonstrated that Mexico-born males, as compared to the other groups, had significantly higher HbA1c levels. Further research is necessary to better understand the relationships among these factors. However, findings do demonstrate a need for more objective disease classification, particularly when examining immigration status and diabetes. Additionally, the complexity of these interactions establishes a need for specific health intervention for foreign-born populations which might be missed by self-report screening asking about presence of disease and exacerbated by an oversimplification of the “healthy immigrant effect”.