Devices and implantation methods utilizing subcutaneous placement into a patient are disclosed for the insertion, advancement and positioning of a subcutaneous implantable medical device (SIMD) such as a medical electrical lead. The SIMD is releasably-engaged with a device in accordance with embodiments of this disclosure, and advanced from an incision of the patient to an implant location. The implantation device may be disengaged from the SIMD without moving the SIMD from the implant location.