OBJECTIVE: To provide a snapshot of the profile of adults and youth with type 1 diabetes (T1D) in the United States and assessment of longitudinal changes in T1D management and clinical outcomes in the T1D Exchange registry. RESEARCH DESIGN AND METHODS: Data on diabetes management and outcomes from 22,697 registry participants (age 1-93 years) were collected between 2016 and 2018 and compared with data collected in 2010-2012 for 25,529 registry participants. RESULTS: Mean HbA1c in 2016-2018 increased from 65 mmol/mol at the age of 5 years to 78 mmol/mol between ages 15 and 18, with a decrease to 64 mmol/mol by age 28 and 58-63 mmol/mol beyond age 30. The American Diabetes Association (ADA) HbA1c goal of <58 mmol/mol for youth was achieved by only 17% and the goal of <53 mmol/mol for adults by only 21%. Mean HbA1c levels changed little between 2010-2012 and 2016-2018, except in adolescents who had a higher mean HbA1c in 2016-2018. Insulin pump use increased from 57% in 2010-2012 to 63% in 2016-2018. Continuous glucose monitoring (CGM) increased from 7% in 2010-2012 to 30% in 2016-2018, rising >10-fold in children <12 years old. HbA1c levels were lower in CGM users than nonusers. Severe hypoglycemia was most frequent in participants >/=50 years old and diabetic ketoacidosis was most common in adolescents and young adults. Racial differences were evident in use of pumps and CGM and HbA1c levels. CONCLUSIONS: Data from the T1D Exchange registry demonstrate that only a minority of adults and youth with T1D in the United States achieve ADA goals for HbA1c.