ObjectiveTo estimate the prevalence of diagnosed total diabetes, type 1 diabetes, and type 2 diabetes in the US general population and the proportions of each among US adults with a diagnosis of diabetes.DesignNationwide, population based, cross sectional survey.SettingNational Health Interview Survey, 2016 and 2017.ParticipantsAdults aged 20 years or older (n=58 186), as a nationally representative sample of the civilian, non-institutionalized US population.Main outcome measuresPrevalence of diagnosed diabetes, type 1 diabetes, and type 2 diabetes in the US general population, and the proportions of each subtype in participants with a diagnosis of diabetes.ResultsAmong the 58 186 included adults, 6317 had received a diagnosis of diabetes. The weighted prevalence of diagnosed diabetes, type 1 diabetes, and type 2 diabetes among US adults was 9.7% (95% confidence interval 9.4% to 10.0%), 0.5% (0.5% to 0.6%), and 8.5% (8.2% to 8.8%), respectively. Type 1 diabetes was more prevalent among adults with lower education level, and type 2 diabetes was more prevalent among older adults, men, and those with lower educational level, lower family income level, and higher body mass index (BMI). Among adults with a diagnosis of diabetes, the weighted percentage of type 1 and type 2 diabetes was 5.6% (4.9% to 6.4%) and 91.2% (90.4% to 92.1%), respectively. The percentage of type 1 diabetes was higher among younger adults (age 20-44 years), non-Hispanic white people, those with higher education level, and those with lower BMI, whereas the percentage of type 2 diabetes was higher among older adults (age ≥65 years), non-Hispanic Asians, those with lower education level, and those with higher BMI.ConclusionThis study provided benchmark estimates on the national prevalence of diagnosed type 1 diabetes (0.5%) and type 2 diabetes (8.5%) among US adults. Among US adults with diagnosed diabetes, type 1 and type 2 diabetes accounted for 5.6% and 91.2%, respectively.