All medical devices, including personalized/custom-made (patient-matched) devices, devices made under the healthcare institution exemption (point-of-care manufacturing) and 3D printed medical devices have to adhere to the applicable parts of Annex I of the MDR.
This IMDRF/GRRP WG/N47 FINAL:2024 (Edition 2) guidance document might help to make sense of the Essential Principles of Safetyand Performance: