On properties less than 25 years old you can usually get away with re-using if installed correctly because at this time builders started using pre-painted steel which is a very long lasting product. Check with your roofing provider to make sure it is re-caulked and re-painted.

On properties 25 years and older, ideally it is a very good idea and recommended to replace. They used to use a type of galvanized metal which does not last very long under harsh weather conditions on your roof, creating rust outs in critical areas.