According to MDR Annex III, a PMS plan contains
A PMCF plan is always required. It might not be applicable for devices that have no direct influence on the patient, e.g. disinfectants. Or when the device is used in another device, e.g. dental implant colouring agents.
Always remember: PMCF ≥ PMCF study. You can often justify not to perform PMCF studies, but you can rarely justify not to perform any PMCF at all.