The term obviously varies by State, but notice the term 'master' is used to describe licensing and that is used by the State itself.
18 years of age. 4000 hours. Not less than two years.... Master? From journeyman to master in less time than is takes to get a journeyman's card? Things need to be taken into context. Plumbing is a whole lot more than simply turd herding and only a few can see everything let alone keep up with changes as time progresses.Master Plumber License
•Must be at least 18 years of age.
•Must have 4,000 hours experience in work as a journey plumber over a period of not less than 2 years immediately preceding the date of the application.
•Must pay the examination fee and pass the examination.
•Must pay the license fee.
I doubt a young "master plumber" in Escanaba MI is 100% capable of doing hi-rise and underground work in Manhattan without having to learn something new first.