There are many different avenues that you can take if you hope to start a career as a plumber.  For example, you might enroll in a technical school or a community college in order to obtain formal education in plumbing.  Another option is to receive on-the-job training or to enter into an apprenticeship program.  Apprenticeship programs are generally administered through the local union or through nonunion contractor organizations.  Whether sponsored by a union or not, an apprenticeship program generally takes four to five years to complete, though apprentices do receive paid on-the-job training through these programs.  In addition to the hands-on experience, apprenticeship programs usually require completion of at least 144 hours of classroom instruction as well.