An interspinous process spacer insertion device that positions an interspinous process spacer between the spinous process of adjacent vertebrae in a minimally invasive percutaneous surgical procedure. The device includes a trocar rod that extends through a cannulated sleeve. The spacer is attached to the end of the cannulated sleeve, where a trocar tip of the trocar rod extends through the spacer. The trocar rod is moved through the cannulated sleeve and an incision in the patient, and is positioned between the spinous process of the vertebra to align the device. The cannulated sleeve is then moved down the trocar rod so that the spacer slides between the spinous process, and the trocar rod is then withdrawn from the patient. The spacer is then rotated so that it locks behind the spinous process, and the cannulated sleeve is detached from the spacer and removed from the patient.