A surgical instrument system includes an end effector, a generator, and a controller. The end effector includes an ultrasonic blade and at least one electrode surface. The generator provides power to the end effector. The end effector applies ultrasonic energy to tissue via the blade or RF energy to tissue via the at least one electrode surface. The controller is configured to select between one or both of ultrasonic energy or RF energy, and thereby control the generator to provide the selected one or both of ultrasonic energy or RF energy at the end effector, based on a sensed operating condition of the end effector. The controller may select between ultrasonic energy and RF energy based on whether a clamp arm is in an open position relative to the blade, based on which button is being activated, and based on whether tissue is sensed at the end effector.