Plumbing Contractor License in Colorado: Requirements, Qualifier, Bond and Exams

Statewide.

Colorado licenses plumbers through the State Plumbing Board (Division of Professions and Occupations, DORA) at three levels: Residential Plumber, Journeyworker Plumber and Master Plumber, and the same program holds the business.

A plumbing company must register as a Plumbing Contractor with the board, and the registration is renewable.

The state credential is not the whole story: Denver runs its own contractor licensing, and a state plumbing license satisfies the first step of Denver's process — the city section below has the detail.

The State Plumbing Board (Division of Professions and Occupations, DORA) runs the program.

For the business, the sources we read describe a single Plumbing Contractor registration, with no class split by job value, project size or residential versus commercial work.

The program also registers Water Installers and Water Principals for water-conditioning work; whether a particular company needs that registration alongside the Plumbing Contractor registration is a question to put to the board.

The individual licenses behind your crew are Residential Plumber, Journeyworker Plumber and Master Plumber, and the top one belongs to your qualifier.

Colorado's qualifier is the Responsible Master Plumber.

The contractor names one, and that person signs an Acknowledgment of Responsibility form affirming the package at once: they hold a Colorado Master Plumber license, they are actively engaged in a full-time capacity, and they assume responsibility for all plumbing work the contractor performs.

Staff to that wording rather than around it — the affirmation describes a working, responsible role, not a name on file.

The license underneath is the state's top individual tier: a Master Plumber applicant must furnish evidence of five full-time years (8,500 hours) of practical experience, and one full-time month counts as 163 hours.

The exams on record are the individual plumber exams, and your qualifier's Master Plumber exam is the one sitting behind the registration.

Colorado plumbing exams are given in English through PSI, and the pass marks differ by level: 70% for Residential and Journeyworker examinees, 75% for the Master examinee.

What the pages we read do not describe is a separate business-and-law exam for the Plumbing Contractor registration itself, so treat that as unconfirmed — ask the board what the registration application requires beyond the named qualifier's license.

This is a gap in our research, not a confirmed absence.

The Colorado plumbing contractor sources we read did not state a bond amount, a bond form or an insurance minimum for the Plumbing Contractor registration, and we will not guess at one.

Ask the State Plumbing Board what it currently requires before you commit to a start date.

HVACHires' separate guide to contractor license bonds and insurance explains how these instruments work in general.

The registration is renewable, but the amounts were not verified: the pages we read did not state the registration or renewal fees, and we could not confirm the renewal cycle either — ask the board's plumbing program for the current fee schedule.

One clock the research does pin down belongs to your qualifier: a Colorado plumber's license runs on a two-year license period, and the licensee must complete at least 8 hours of approved continuing education during each year (March 1 through February 28) of that period.

An owner-operator should read that as two calendars to manage: the company registration's renewal, and the Master Plumber license's continuing education, which keeps the qualifier itself current.

The sources we read describe no reciprocity route for the Plumbing Contractor registration itself — treat that as a gap and ask the board what applies to an out-of-state plumbing company.

What Colorado does confirm is endorsement one level down, for the individuals: a plumber licensed in another state, with substantially equivalent credentials and a comparable state exam, can seek Colorado licensure by endorsement.

Two limits are explicit.

The license must be state issued — city or county licenses do not qualify — and the applicant must have held it for at least six months.

That endorsement route is one path an out-of-state master can take toward becoming your Responsible Master Plumber.

The registration is only as stable as its affirmation.

The Responsible Master Plumber has affirmed full-time engagement and responsibility for all the company's plumbing work, so a departure leaves that affirmation standing without the person behind it.

What our research did not verify is a replacement deadline — the pages we read did not state one — so contact the board promptly and ask what it expects in the gap, and how the registration is treated in the meantime.

Building a replacement takes lead time: the new qualifier needs a Master Plumber license, which takes five full-time years and 8,500 hours of documented experience, plus the willingness to take the full-time, all-work responsibility the form describes.

HVACHires has a separate guide to naming a qualifier or qualifying agent for a contractor license.

Denver is the city layer our research covers.

Denver's contractor licensing is a two-step process: before applying for the city's contractor license, an applicant must hold a supervisor certificate or a state electrical or plumbing license — the category your qualifier's Master Plumber license falls in — or employ someone who holds a supervisor certificate.

The city license is separate from the state Plumbing Contractor registration and carries its own application.

Outside Denver, our research did not map city-by-city plumbing contractor licensing, so check with the city or county where each job's permit is pulled before you schedule work there.

In June 2026 the State Plumbing Board held a rulemaking hearing to adopt new editions of the International Plumbing Code, the Fuel Gas Code and the International Residential Code.

Which editions the board adopted is not part of our research, and the hearing's outcome is not confirmed in our sources, so do not anchor bids, material orders or study plans to a specific code edition.

Code editions matter to a contractor's daily work, so check the board's plumbing program page for the currently adopted editions before you price code-sensitive work.