The present application is directed to devices and methods for releasing tension on a surgical tether. In one embodiment, the release mechanism is constructed to be positioned between a locked position and a release position. In the locked position, the release mechanism is attached to the tether to prevent the tether from moving through the release mechanism. In the release position, the release mechanism allows the tether to move through the body. The release mechanism may be constructed to move between the release and locked positions after being implanted within a patient. In one embodiment, the release mechanism returns to the locked position after the tension on the tether has been reduced below a predetermined amount.