Currently you need to know what category your patient will fall into when creating their account. You cannot change or move a current patient into a different category. Now that categories can be used for Patient Messaging adjustments and groups, it would be nice to enable those patients that need to message a bit more than you would like to allow most to message a higher or maybe lower number of messages. Even temporarily. This would allow managers or admins to change Patients categories when needed which seems like why you would attach messaging rules to the Patient Categories option. Maybe this is an unfinished feature??