Importance: An estimated 13% of all US adults (18 years or older) have diabetes, and 34.5% meet criteria for prediabetes. The prevalences of prediabetes and diabetes are higher in older adults. Estimates of the risk of progression from prediabetes to diabetes vary widely, perhaps because of differences in the definition of prediabetes or the heterogeneity of prediabetes. Diabetes is the leading cause of kidney failure and new cases of blindness among adults in the US. It is also associated with increased risks of cardiovascular disease, nonalcoholic fatty liver disease, and nonalcoholic steatohepatitis and was estimated to be the seventh leading cause of death in the US in 2017. Screening asymptomatic adults for prediabetes and type 2 diabetes may allow earlier detection, diagnosis, and treatment, with the ultimate goal of improving health outcomes. Objective: To update its 2015 recommendation, the USPSTF commissioned a systematic review to evaluate screening for prediabetes and type 2 diabetes in asymptomatic, nonpregnant adults and preventive interventions for those with prediabetes. Population: Nonpregnant adults aged 35 to 70 years seen in primary care settings who have overweight or obesity (defined as a body mass index > > =25 and > /=30, respectively) and no symptoms of diabetes. Evidence Assessment: The USPSTF concludes with moderate certainty that screening for prediabetes and type 2 diabetes and offering or referring patients with prediabetes to effective preventive interventions has a moderate net benefit. Conclusions and Recommendation: The USPSTF recommends screening for prediabetes and type 2 diabetes in adults aged 35 to 70 years who have overweight or obesity. Clinicians should offer or refer patients with prediabetes to effective preventive interventions. (B recommendation).