Colorado Master Plumber License Requirements (2026)

The Colorado Department of Regulatory Agencies (DORA) State Plumbing Board licenses every plumber in the state under Colorado Revised Statutes Title 12 Article 155. DORA issues four individual credentials — Apprentice, Residential Plumber, Journeyman Plumber, and Master Plumber — plus a Plumbing Contractor business registration that requires a Master as the qualifying party. The Journeyman path requires 10,500 hours of on-the-job training and 288 classroom hours. The Master Plumber path requires the Journeyman credential plus two additional years (4,000 hours) of journey-level work and a separate ICC examination. Colorado adopts the International Plumbing Code with state amendments and enforces statewide permitting rules on any project subject to a plumbing permit.

Regulatory Oversight

Colorado Department of Regulatory Agencies — State Plumbing Board (DORA) administers and enforces this credential under the authority of Colorado Revised Statutes Title 12 Article 155 (Plumbers); 3 CCR 720-1. The DORA State Plumbing Board licenses Apprentice, Residential, Journeyman, and Master Plumbers, registers Plumbing Contractors, adopts the International Plumbing Code as amended by Colorado, and conducts disciplinary proceedings.

Official portal: https://dpo.colorado.gov/Plumbing
Address: 1560 Broadway, Suite 1350, Denver, CO 80202
Phone: (303) 894-7800

Who May Apply

At a minimum the applicant has to be 18 years old and supply a valid Social Security Number. No Colorado residency requirement.

Good moral character

DORA conducts a fitness review on every applicant. Felony convictions and prior license discipline are reviewed individually.

Background investigation

Mandatory criminal history disclosure on the application; DORA may request additional documentation for unresolved items.

Required Experience and Education

Eligibility requires five years and 10,500 hours of qualifying plumbing experience plus 288 classroom hours of related instruction to reach the Journeyman credential, then two additional years (4,000 hours) of journey-level experience under a licensed Master Plumber to qualify for the Master Plumber examination., documented and independently verifiable. Payroll, tax, project, and supervisor records are the usual proof the board will accept.

Accepted proof of experience or eligibility

DORA experience affidavit signed by each licensed Master Plumber supervisor
W-2 statements, pay stubs, or 1099 records covering the qualifying period
Approved plumbing apprenticeship completion certificate (where applicable)
Transcripts proving the 288 classroom hours of related instruction

Education substitution

A US Department of Labor registered plumbing apprenticeship satisfies both the hour requirement and the 288 classroom hours. Accredited plumbing technology coursework substitutes on a sliding scale set by DORA rule.

Examination Requirements

PSI Services LLC under contract to DORA; ICC content for Journeyman and Master plumber examinations runs the examination for this credential. Issuance is contingent on passing every part below:

Colorado Master Plumber Examination — International Plumbing Code, Colorado amendments, theory, and calculations — 100 questions, 300 minutes, passing score 70%

Examination fee: $88 examination fee paid to PSI on the day of testing.

Retake policy: Failed examinations may be re-taken by paying a new $88 fee. Each application remains valid for one year.

Insurance and Financial Requirements

The cited materials impose no contractor license bond for this credential. Bear in mind that specific contracts, permits, or public works can still require their own bonds.

General liability

DORA does not impose a state-level general liability minimum on individual plumbers. Plumbing Contractor business registrations must show proof of general liability acceptable to the registering municipality.

Workers' compensation

Workers' compensation insurance is mandatory in Colorado under CRS 8-44-101 et seq. for any business with one or more employees including part-time.

Additional financial requirements

No DORA financial statement is required for individual credentials. Plumbing Contractor business registrations require proof of insurance and an active Colorado business registration.

Licensing Fees

Fee	Amount
Application (non-refundable)	$88
Examination	$88
Initial license	$88
Renewal (every 3 years)	$88

Keeping the License Current

Renewal of the Colorado Master Plumber (and Plumbing Contractor Registration) comes due every 3 years. As cited, the renewal fee stands at $88. Colorado plumber credentials renew every three years. Lapsed credentials beyond two years require re-application and may require re-examination.

Continuing education: 16 hours of DORA-approved continuing education each three-year renewal cycle on the current International Plumbing Code and Colorado amendments.

Downloadable Asset

2026 Colorado Plumber License Roadmap (PDF) — a printable step-by-step checklist for the application process.

Download the PDF roadmap →

Reciprocity and License Transfer

The NASCLA Accredited Examination is not accepted by Colorado for this classification.

Reciprocal State	Accepted Exam	Conditions
Wyoming	Master Plumber exam waived	Bilateral DORA–Wyoming reciprocity for active master plumbers in good standing for at least one year.
New Mexico	Trade exam waived	Bilateral DORA–New Mexico reciprocity for active journeyman and master plumbers.
Nebraska	Trade exam waived	Bilateral DORA–Nebraska reciprocity for active journeyman plumbers.

Colorado maintains limited bilateral plumber reciprocity with neighboring states. Reciprocal applicants still must pass the Colorado-specific code amendments portion and pay full DORA fees.

Weighing more than one jurisdiction? The national hub compares Plumber license requirements in every state — exam, bond, fee, and experience thresholds side by side.

Application Process, Step by Step

Register as an Apprentice Plumber. DORA requires every plumbing worker to be registered before performing work. Apprentices must be registered with an approved program.
Complete 10,500 hours and 288 classroom hours. Five years of supervised plumbing experience plus 288 classroom hours of related instruction to qualify for the Journeyman exam.
Pass the Journeyman Plumber examination. Score 70% or better on the ICC Journeyman exam administered by PSI.
Work two years as a Colorado Journeyman. Complete two additional years (4,000 hours) of journey-level experience under a licensed Master Plumber.
Submit the DORA Master Plumber application. File the application with the experience affidavit, classroom hour transcripts, and exam fee.
Pass the Master Plumber examination at 70%. Sit the 100-question, five-hour ICC Master Plumber exam at a PSI test center.
Register as a Plumbing Contractor (if self-employed). File a separate Plumbing Contractor business registration with DORA naming the Master Plumber as the qualifying party.

Document Checklist

The items below are the ones worth confirming before the application is filed with DORA:

☐ DORA apprentice registration on file before any plumbing work
☐ Documentation of 10,500 hours and 288 classroom hours for the Journeyman exam
☐ Journeyman Plumber credential (prerequisite for Master)
☐ Documentation of two additional years (4,000 hours) of journey-level experience
☐ PSI Master Plumber exam pass certificate at 70%+
☐ Plumbing Contractor registration (if self-employed)
☐ Colorado workers compensation certificate (any business with one or more employees)

Recommended References

What follows are the regulator-cited and commonly used preparation references for this trade. They appear here for convenience only; CLR takes no compensation for them.

International Plumbing Code, Colorado-adopted edition with amendments — International Code Council. Primary technical reference. Open-book at the PSI test center.
Plumber's Exam Preparation Guide — Howard C. Massey — Craftsman Book Company. Widely used by Colorado applicants for IPC calculation and sizing problems.
Ferguson Master Plumber Exam Prep — Ferguson Publishing. Comprehensive review matched to the ICC master plumber content outline.

Frequent Application Errors

Drawn from the board instructions and sources cited on this page, the pitfalls below are the ones most likely to slow down or sink a Colorado Plumber application.

Skipping apprentice registration

DORA requires every plumbing worker to be registered before performing work. Hours worked while unregistered do not count toward the 10,500-hour requirement.

Missing the 288 classroom hours

On-the-job hours alone are not enough. Without 288 documented classroom hours of related instruction, DORA rejects the Journeyman application.

Studying the wrong IPC edition

Colorado adopts the IPC with local amendments on a delayed cycle. Confirm the current adopted edition and amendment list with DORA before studying.

Confusing master credential with contractor registration

The Master Plumber credential authorizes you as an individual; you still need a separate Plumbing Contractor business registration to bid work as a company.

Letting the credential lapse

A lapsed Master Plumber credential automatically suspends any Plumbing Contractor registration that depends on it as the qualifying party.

Other Colorado Trade Licenses

CLR covers other Colorado trades as well — the published guides below may be more relevant:

Questions Applicants Ask

What are the four Colorado plumber credentials?

Apprentice (registered trainee), Residential Plumber (one and two-family dwellings only), Journeyman Plumber (full scope under supervision), and Master Plumber (supervises journeymen and pulls permits). The Plumbing Contractor registration is a separate business credential.

How many hours does Colorado require for a Journeyman Plumber?

Five years and 10,500 hours of qualifying plumbing experience plus 288 classroom hours of related instruction. A US DOL registered apprenticeship satisfies both requirements.

How long does it take to become a Master Plumber in Colorado?

Seven years total: five years (10,500 hours) to reach Journeyman, plus two additional years (4,000 hours) of journey-level work to qualify for the Master examination.

Does Colorado reciprocate plumber credentials?

Yes, with limits. DORA maintains bilateral reciprocity with Wyoming, New Mexico, and Nebraska. Reciprocal applicants must still pass the Colorado-specific code amendments portion.

How often does the Colorado Master Plumber credential renew?

Every three years. Renewal requires continuing education on the current International Plumbing Code and Colorado amendments.

Primary Sources

Regulatory requirements on this page are drawn from the official board, statute, and exam-provider materials listed below.

Verified 2026-06-05 · Next scheduled review 2026-09-03