• Age ≥6.0 and ≤13 years old at time of consent

• Clinical diagnosis, based on investigator assessment, of type 1 diabetes for at least one year

• Currently using insulin pump for at least three months; Any pump, either open loop or hybrid closed loop may be used.

• Currently using insulin for at least six months.

• Willingness to use lispro/aspart in the insulin pump during the study.

• Currently using a Dexcom G6 or G7 CGM.

• Has one or more parent/guardian knowledgeable about emergency procedures for severe hypoglycemia and able to contact emergency services and study staff that live with participant.

• Participant not currently known to be pregnant or breastfeeding.

• If participant capable of becoming pregnant, must agree to use a form of contraception to prevent pregnancy while a participant in the study (e.g. hormonal contraception, abstinence from heterosexual intercourse). A negative serum or urine pregnancy test will be required for all females of childbearing potential. Participants who become pregnant will be discontinued from the study. Also, participants who during the study develop and express the intention to become pregnant within the timespan of the study will be discontinued.

⁃ Willingness to use the study FCL system (CGM, pump, and phone) during the relevant study period.

⁃ Willingness not to start any new non-insulin glucose-lowering agent during the course of the trial.

⁃ Willingness to participate in all study procedures including the house/hotel session and to consume approximately 3 unannounced meals per day during the relevant portion of the supervised hotel session.

⁃ Access to internet at-home and willingness to upload data during the study as needed.

⁃ Investigator has confidence that the participant can successfully operate all study devices and is capable of adhering to the protocol.

⁃ Participant is proficient in reading and writing English.