Colorado’s Journeyworker Plumber credential — the credential name in use since July 1, 2025 — is examined through PSI on the 2024 International Plumbing Code and the 2024 International Residential Code. The examination transitioned to those editions on November 1, 2026, and it now sits ahead of the code Colorado has adopted, which remains the 2021 International Plumbing Code under the 2023 Colorado Plumbing Code. For this sitting, the examination governs. The PassProfessor Colorado Journeyworker Plumber program prepares candidates for that examination and for the edition discipline it demands.
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What this credential certifies
The Colorado Journeyworker Plumber is the examined journey-level plumbing credential in Colorado. It certifies that the holder has demonstrated, by examination, working command of the plumbing code material Colorado tests at the journey level — the installation, sizing, protection, and inspection logic that governs plumbing systems in the field. A journeyworker works the trade at the journeyman level of responsibility: reading a system as a whole, sizing its parts so they work together, protecting potable water, carrying waste safely away, and recognising where a proposed installation departs from the code that governs it.
The name itself carries a Colorado fact every candidate should absorb before anything else. Effective July 1, 2025, Colorado renamed this credential: it is the Journeyworker Plumber. Candidates will still encounter the older journey-level wording in older study material, in conversation, and in material prepared before the rename. On current Colorado documents, in the examination registration, and throughout this page and its companion guide, the credential is the Journeyworker Plumber, and candidates should learn to search, register, and correspond under that name.
The examination at a glance
| Item | Verified position |
|---|---|
| Program | Colorado Journeyworker Plumber — the examined journey-level plumbing credential in Colorado |
| Credential name | Journeyworker Plumber — the name in use since the rename effective July 1, 2025 |
| Examination vendor | PSI |
| Examination references | 2024 International Plumbing Code and 2024 International Residential Code |
| Examination transition | The examination transitioned to the 2024 editions on November 1, 2026; the 2021 book remains allowed on request until February 1, 2027 |
| Adopted code | 2021 International Plumbing Code, under the 2023 Colorado Plumbing Code — the examination is ahead of the adopted code, and the examination governs for the sitting |
| Passing standard | 70 percent, as published for the Colorado examinations in the PSI candidate information material |
| Companion guide | Colorado Journeyworker Plumber Exam Guide: /colorado-journeyman-plumber-exam-guide/ |
| Administrator note | PassProfessor is independent and is not affiliated with the Colorado Department of Regulatory Agencies or with PSI |
The Colorado delta: an examination ahead of the adopted code
Most examination preparation assumes one code edition does two jobs — the edition adopted for work in the field and the edition printed on the examination. Colorado currently separates those jobs, and the separation is the single most important fact on this page.
Colorado’s adopted plumbing code position is the 2021 International Plumbing Code, carried under the 2023 Colorado Plumbing Code. The Journeyworker Plumber examination, by contrast, transitioned on November 1, 2026 to the 2024 International Plumbing Code and the 2024 International Residential Code. Stated plainly: the examination tests a later edition than the code currently adopted for Colorado work. A candidate who studies only the adopted 2021 material is studying the field code, not the tested code. A candidate who assumes the two must match — because they match in most other states and matched in Colorado practice material prepared earlier — will prepare for the wrong sitting.
The rule for this program, and for any Colorado candidate, follows directly: for the sitting, the examination governs. Prepare on the 2024 International Plumbing Code and the 2024 International Residential Code. Treat the 2021 edition as background and as field context, and treat every difference between the editions as a place where the sitting can — and characteristically will — test whether the candidate knows which book they are being examined on.
One transition detail belongs in every candidate’s diary. During the transition window, the 2021 book remains allowed on request until February 1, 2027. That allowance is a transition accommodation, not a change in what the examination tests. A candidate who sits during the window should decide deliberately which edition they will work from, request the 2021 book only as a considered choice under that allowance, and understand that the examination’s reference position is the 2024 editions. After February 1, 2027, the allowance ends and the 2024 position stands alone.
Why two code books: the IPC and the IRC together
Colorado examines the Journeyworker Plumber on two books, and the pairing is deliberate. The International Plumbing Code carries the general plumbing code: fixtures, water supply and distribution, sanitary drainage, indirect and special waste, vents, traps, interceptors and separators, storm drainage, and the administrative and definitional framework that holds those systems together. The International Residential Code carries the plumbing provisions as they apply in the residential setting — the one- and two-family and townhouse work where a large share of journey-level plumbing is actually performed, stated in the residential book’s own organisation and numbering.
A journeyworker in Colorado moves between those settings constantly. The same installer who roughs in a commercial washroom in the morning may trim out a residence in the afternoon, and the code answers for sizing, venting, cleanouts, and protection do not always sit in the same chapter or table in the two books. The examination’s two-book structure mirrors the trade’s real shape. Preparation that treats the residential material as a shortened version of the general code will miss the places where the residential provisions state their own requirements, and preparation that ignores the general code’s full system logic will miss the commercial and mixed work the credential also covers. This program teaches the two books as a pair: the same system, read in both of its tested forms.
What the examination covers
The tested material follows the two code books, and its centre of gravity is the working knowledge a journeyworker uses daily.
Water supply and distribution — examined as sizing and protection: demand and load, pressure and its losses, materials and joints, backflow protection and cross-connection control, and the valves and access that make a system serviceable. Items characteristically give a system, not a definition, and ask what the code requires it to do.
Sanitary drainage — examined as the drainage system’s sizing and slope logic: drainage fixture units, building drains and sewers, stacks and branches, cleanout placement, and the materials and fittings that keep flow moving in the intended direction at the intended grade.
Vents and venting — examined as the drainage system’s other half: why venting protects trap seals, how vent sizing and distance rules work, and how the recognised venting arrangements differ. Venting errors are quiet in the field and loud on this examination; candidates who treat venting as an afterthought to drainage consistently underperform.
Traps, interceptors, and separators — examined as protection devices with specific duties: trap construction and prohibitions, and the interceptors and separators that keep grease, oil, sand, and other harmful material out of the system they would damage.
Fixtures and fixture fittings — examined as count, type, installation, and clearance: what a given occupancy requires, how fixtures connect to water and waste, and where accessibility and clearances constrain the layout.
Indirect and special waste, and storm drainage — examined as the systems that handle what ordinary direct connection cannot: air gaps and air breaks, waste from equipment and processes with special character, and the sizing and routing of storm water away from the building.
Residential plumbing under the IRC — examined in the residential book’s own terms: water service and distribution in dwellings, dwelling drainage and venting, fixture installation in residential settings, and water heater installation as the residential provisions state it. The candidate must be able to find and apply the residential answer, not merely assume it matches the general code.
Administration, definitions, and general regulation — examined as the framework that makes the technical chapters enforceable: the code’s defined terms used in their code sense, permit and inspection logic, materials standards, and the general rules on workmanship, protection of the system, and protection of the building structure the system passes through.
The passing standard, stated once and plainly
The passing standard for the Colorado Journeyworker Plumber examination is 70 percent, as published for the Colorado examinations in the PSI candidate information material. Candidates researching Colorado online will encounter other figures in older and secondary material. The figure this program is built to, the figure stated in the companion guide, and the figure a candidate should carry into planning is 70 percent. Preparation should be organised around clearing that standard in the tested material as a whole — which means no major system area can be left as a known weakness on the assumption that strength elsewhere will carry it comfortably. Steady coverage across water, waste, and venting, in both books, is what a 70 percent standard rewards.
The route, in order
The route runs in the order the system itself imposes. Confirm the credential — the Journeyworker Plumber, under its current name — and confirm that the journey-level examination is the step in front of you. Register for the examination through PSI, the examination vendor for this credential, following the current PSI candidate information for the Colorado Journeyworker Plumber examination. Prepare on the tested editions — the 2024 International Plumbing Code and the 2024 International Residential Code — observing the transition allowance for the 2021 book, available on request until February 1, 2027, as a deliberate choice rather than a default. Sit the examination and meet the 70 percent standard. Complete the credential steps that follow a pass through Colorado’s own channels, under the Journeyworker Plumber name. Candidates should verify current administrative details directly with Colorado and with PSI at the time they register, because this page states the verified examination position — vendor, editions, transition, and standard — and does not restate administrative figures that belong to the live registration process.
What makes this examination demanding
Colorado’s difficulty is concentrated in one place, and it is not obscurity. The examination is current — it moved to the 2024 editions on November 1, 2026 — while much of the material in circulation, and the code adopted for Colorado work, still speaks 2021. Every habits-of-study trap follows from that gap. Tables remembered from the adopted edition, sizing rules learned on a job governed by the adopted code, and practice material assembled before the transition all feel like preparation and can quietly be preparation for a different examination. The second demand is the two-book pairing: the candidate must hold the general code and the residential code at once and know which book a question is standing in. The third is the ordinary, durable demand of journey-level plumbing itself — systems reasoning. Sizing, venting, and protection questions reward the candidate who sees the whole system the item describes; they punish the candidate who memorised isolated rules without the system that gives them meaning.
What the PassProfessor program will cover
Built for the tested editions, in the tested pairing. The PassProfessor Colorado Journeyworker Plumber program is written to the 2024 International Plumbing Code and the 2024 International Residential Code as PSI examines them. The adopted 2021 edition appears in the program where the contrast itself teaches — where a candidate working under the adopted code must consciously set a field habit aside for the sitting — and never as the tested answer. The program’s companion, the Colorado Journeyworker Plumber Exam Guide, works through the credential, the transition, and the study method in full.
Edition discipline as the teaching method. Items are organised so the candidate always knows which book and which edition an answer stands in. Where the general code and the residential code treat the same system differently, the program teaches the difference directly rather than hoping the candidate notices it. Where the 2024 editions differ from the 2021 material a candidate already knows, that difference is the lesson.
Original material, primary sources. Every item in the program is written from scratch against the tested code material and the published Colorado examination position. No item is drawn from another provider’s material, and no item asks a candidate to memorise a citation as a substitute for understanding the system the citation governs.
Independence, stated plainly. PassProfessor is an independent preparation provider, not affiliated with the Colorado Department of Regulatory Agencies or with PSI, and this program is not a Colorado course and not a PSI course. Completing it confers no credential and no exemption. Colorado credentials; PSI examines; candidates register for the examination through PSI’s channels.
Tell me when enrollment opens. The Colorado Journeyworker Plumber program is in the works and enrollment is not yet open. Our catalog now includes Colorado journey-level plumbing preparation among the trade programs in preparation, and this program will open when it meets the standard described above. Leave an email address and PassProfessor will write to you when the program is ready — and only about this program. No date is promised.
Frequently asked questions
What is the credential called?
The Journeyworker Plumber. Colorado renamed the credential effective July 1, 2025, and Journeyworker Plumber is the name in current use on Colorado documents and in examination registration.
Who administers the Colorado Journeyworker Plumber examination?
PSI is the examination vendor for this credential. Candidates register and schedule through PSI’s channels, following the current PSI candidate information for the Colorado examination.
What code editions does the examination test?
The 2024 International Plumbing Code and the 2024 International Residential Code. The examination transitioned to those editions on November 1, 2026.
What code has Colorado adopted?
The 2021 International Plumbing Code, under the 2023 Colorado Plumbing Code. The examination is ahead of the adopted code — the tested edition and the adopted edition are not the same in Colorado at present.
Which edition should I study?
The tested editions: the 2024 International Plumbing Code and the 2024 International Residential Code. For the sitting, the examination governs.
What about the 2021 book during the transition?
The 2021 book remains allowed on request until February 1, 2027. Treat that as a transition allowance to use deliberately, not as a statement that the examination tests the 2021 editions.
What score passes the Colorado Journeyworker Plumber examination?
70 percent, as published for the Colorado examinations in the PSI candidate information material.
Why does the examination include the International Residential Code?
Because journey-level work in Colorado includes residential plumbing, and the residential provisions are stated in that book in their own organisation. Colorado examines the Journeyworker Plumber on both books.
Is PassProfessor affiliated with Colorado or with PSI?
No. PassProfessor is an independent preparation provider. Colorado credentials plumbers and PSI administers the examination; PassProfessor prepares candidates for it.
Where can I read the full breakdown?
In the companion Colorado Journeyworker Plumber Exam Guide, which covers the credential, the edition transition, the tested material, and a study plan built around them.
When does enrollment open?
The program is in the works and enrollment is not yet open. Leave an email address on this page and PassProfessor will write to you when the program is ready — and only about this program.