OBJECTIVE: Changes in the prevalence, treatment, and management of diabetes in the United States from 1999 to 2006 were studied using data from the National Health and Nutrition Examination Survey. METHODS: Data on 17,306 participants aged 20 years or more were analyzed. Glycemic, blood pressure, and cholesterol targets were glycosylated hemoglobin less than 7.0%, blood pressure less than 130/80 mm Hg, and low-density lipoprotein (LDL) cholesterol less than 100 mg/dL, respectively. RESULTS: The prevalence of diagnosed diabetes was 6.5% from 1999 to 2002 and 7.8% from 2003 to 2006 (P <.05) and increased significantly in women, non-Hispanic whites, and obese people. Although there were no significant changes in the pattern of antidiabetic treatment, the age-adjusted percentage of people with diagnosed diabetes achieving glycemic and LDL targets increased from 43.1% to 57.1% (P <.05) and from 36.1% to 46.5% (P <.05), respectively. Glycosylated hemoglobin decreased from 7.62% to 7.15% during this period (P <.05). The age-adjusted percentage achieving all 3 targets increased insignificantly from 7.0% to 12.2%. CONCLUSIONS: The prevalence of diagnosed diabetes increased significantly from 1999 to 2006. The proportion of people with diagnosed diabetes achieving glycemic and LDL targets also increased. However, there is a need to achieve glycemic, blood pressure, and LDL targets simultaneously.