An insertion device for inserting an infusion device at least partially into skin for subcutaneous infusion can comprise a sleeve having a lower surface that is configured to engage the skin, a shuttle or carriage to carry the infusion device between a retracted position and an advanced position; at least a first biasing member to urge the shuttle or carriage toward the advanced position, and an actuator to cause the first biasing member to urge the carriage from the retracted position to the advanced position. In some embodiments, the insertion device can further comprise a hub and at least a second biasing member to urge the hub away from the shuttle or carriage. In some embodiments, the insertion device can further comprise a needle attached to the hub. Methods for inserting an infusion device and various other features that can be comprised by an insertion device are also disclosed.