Transitioning to other modes in automated insulin delivery

An ambulatory infusion pump system, comprising:

• a pump mechanism configured to facilitate delivery of insulin to a user;
• a communications interface adapted to receive glucose levels from a continuous glucose monitor;
• at least one processor functionally linked to the pump mechanism and the communications interface, the at least one processor configured to:
• automatically calculate insulin doses with a closed loop delivery algorithm based on glucose levels received from the continuous glucose monitor, the closed loop delivery algorithm configured to calculate the insulin doses to maintain a user's glucose levels within a first target glucose range including a low glucose threshold and a high glucose threshold;
• automatically deliver the insulin doses calculated by the closed loop delivery algorithm to the user with the pump mechanism;
• determine that the first target glucose range should be modified from the first target glucose range to a second target glucose range;
• determine an amount of time elapsed since a most recent bolus delivery of insulin has been delivered by the pump mechanism;
• immediately transition from the first target glucose range to the second target glucose range if the amount of time since the most recent bolus delivery of insulin is greater than a predetermined amount of time from the determination to modify the first target glucose range;
• and
• gradually transition from the first target glucose range to the second target glucose range if the amount of time since the most recent bolus delivery of insulin is less than the predetermined amount of time from the determination to modify the first target glucose range.