OBJECTIVE: To determine whether the use of continuous glucose monitoring (CGM) without confirmatory blood glucose monitoring (BGM) measurements is as safe and effective as using CGM adjunctive to BGM in adults with well-controlled type 1 diabetes (T1D). RESEARCH DESIGN AND METHODS: A randomized noninferiority clinical trial was conducted at 14 sites in the T1D Exchange Clinic Network. Participants were >/=18 years of age (mean 44 +/- 14 years), had T1D for >/=1 year (mean duration 24 +/- 12 years), used an insulin pump, and had an HbA1c