As with other skilled trades, plumbers have different levels of expertise and training. Requirements vary by state, and there could be additional competency requirements for plumbers in your area. As a general rule, these classifications are used to denote a plumber's training:
Apprentice plumber -- Apprenticeship programs generally provide the most comprehensive training for novice plumbers. They're administered either by union locals and their affiliated companies or by nonunion contractor organizations. Apprenticeships typically consist of at least three to four years of paid, on-the-job training and some hours of related classroom instruction.
Journeyman plumber -- Once the requirements of an apprenticeship are fulfilled, plumbers can apply for a journeyman license. Many workers in the plumbing field are journeymen. Obtaining a journeyman's license requires a fee and the successful passing of an exam. Licenses vary by state, although not all areas require journeymen to be licensed. Instead, the amount of work they are able to perform is limited.
Master plumber -- To become a master plumber, a person must have a certain number of years' experience as a journeyman plumber, in addition to an associate degree or training at a vocational school. A master plumber must pass an exam that typically encompasses both written and practical knowledge. They must also complete continuing education hours every year. Oftentimes the business owner, a master plumber is subject to inspection and must make sure all journeyman plumbers working for his or her company are in compliance with plumbing regulations.