Modifier 53 is a modifier that is an example of a procedure that is started but needs to be stopped and not completed. There could be some reasons to use this, such as a surgical procedure that is something small but once the patient is opened up the physician can see the situation is worse than they would have expected and needs to be stopped. Once the patient is awoken they can hear their new options if there is any. An example of this sicario would be a 50 year old male is in for a simple colonoscopy procedure, due to the fact that during the procedure there is a mass blockage and it can not be fully completed. The CPT code for the colonoscopy that was started but could not be completed due to the mass would be 45378 which is colonoscopy without biopsy or removal of polyp with 53 as modifier, for a discontinued procedure. please respond to this post