State Plumbing Board: Licensing Requirements

General Qualifications

The general qualifications for plumbing license outlined in Board Rule 3.0 are follows:

Residential Plumber: You must verify two years (3,400 hours) of practical experience.

Journeyman Plumber: The maximum experience the board requires for an applicant to qualify to receive a journeyman plumber's license is four years (6,800 hours) of practical experience.

Master Plumber: An applicant for a master plumber's license must furnish evidence of having obtained five full-time years (60 months/9,780 hours) of practical experience.

One month of full-time experience is equivalent to 163 hours.

License by Examination

  • Letters of Verification: The applicant must verify plumbing installation experience by submitting an Affidavit of Experience Form from current and former employers (plumbing contractors).
  • Out-of-State Verification: Follow the same procedure as above. Applicants shall not verify their own experience (even if currently licensed in another state). In addition, a photocopy of your out-of-state license is required. However, your out-of-state license is not a substitute for submitting the Affidavit of Experience Form.

Temporary Work Permit: At the time that you apply for the examination, you may request a temporary work permit. Only one 30-day permit may be issued to an applicant.

Examination Information: Examinations are administered in English only through a private testing agency. Once your application has been approved by this office, a letter of acceptance and information on how to contact PSI to obtain a candidate handbook will be provided. The handbook will provide information on who to contact, how to schedule for the written examination, the testing locations, the required fee, and other important information.

The examination is in a multiple-choice format. Questions are based on the currently adopted codes, namely, the International Plumbing Code (IPC), the International Fuel Gas Code (IFGC), and the Rules and Regulations as adopted by the Examining Board of Plumbers. The following is a sample of the categories covered in the written examination: cross connections; calculations and blueprint reading; combination waste and vent systems; hangers, supports and system protection; indirect and special waste piping; installation techniques; plumbing fixtures; sanitary drainage systems; storm drainage systems; traps, interceptors, separators; vents/venting; water distribution systems. An overall score of 70% is required to pass the written portion of the examination for residential and journeyman examinees; 75% is required for the master examinee. Your results will indicate either pass or fail.

License by Endorsement

Licensees from another state may be eligible for licensure by endorsement providing that the applicant possesses credential and qualifications that are substantially equivalent to requirements in Colorado for licensure by examination and you must provide verification of all of the following:

  • Completion of a state or federally approved apprenticeship program, or completion of the required years and type of experience for the comparable license.
  • Submit verification from the state licensing agency of successful completion of a comparable state plumbing examination as outlined under "Documenting Plumbing Experience" and based on the currently adopted Colorado Code.
  • Submit a photocopy of your currently held state (not city or county) issued license which you have held for a minimum of six (6) months.
  • Submit a completed application with letters of verification of your plumbing experience as outlined under "Documenting Plumbing Experience" (above) for the license category for which you are applying for endorsement.

An Apprentice must be registered until such time as the individual has actually obtained a Colorado plumber's license. A plumbing apprentice is any individual employed in the plumbing trade that is not currently licensed in the State of Colorado.

View licensing information for other states.