You get a plumbing license by registering or training as an apprentice, logging supervised work experience, passing your state's journeyman exam and — often years later — the master exam.
There is no national plumbing license: each state, and in some states each city or county, sets the rungs, the hours and the tests.
Here is what each level legally does and how the rules differ across the country.
What is a plumbing license and who needs one?
A plumbing license is a government-issued authorization to install and repair piping systems — water supply, drains, vents, and often gas piping — and it comes from a specific body: a state licensing board, or a city or county licensing office in the states that license locally.
That is what separates a license from a certification.
Industry credentials such as OSHA 10/30 cards, NATE, HVAC Excellence, NCCER and ASSE certificates are voluntary credentials, not government licenses — though a state can wire one into licensing when it wants to (more on that below).
Who needs a license?
Nearly everywhere, it is anyone doing plumbing work beyond the exemptions a jurisdiction allows.
But the line moves with the border: exemption thresholds, journeyman and master definitions, experience hours, continuing-education hours and permit rules are all set state by state, and no federal source defines them.
Licensing is also not the only rule that follows the trade.
Federal OSHA construction standards apply whether your license comes from a state or a city.
One example plumbers meet constantly: every worker in an excavation — a sewer or water-line trench — must be protected from cave-ins by a protective system unless the excavation is entirely in stable rock or is under 5 feet deep with no indication of cave-in, as judged by a competent person, under 29 CFR 1926.652(a)(1).
The license says you may do the work; OSHA says how the trench gets dug.
For the trade itself — the work, the settings and the pay — see our plumber career guide.
What are the plumbing license levels: apprentice, journeyman, master?
The common shape is three rungs plus a business layer.
The apprentice rung is supervised learning: you work on real jobs under qualified plumbers while the skills build.
The journeyman rung is the working license — qualified to do the trade's day-to-day work.
The master rung is the senior license the other two build toward.
Above the ladder sits plumbing contracting: running a business that installs and repairs plumbing for the public.
As of September 29, 2026, 24 states run that classic apprentice/trainee → journeyman → master ladder at the state level.
Texas is a clean example: the Texas State Board of Plumbing Examiners (TSBPE) licenses plumbers statewide, and its four licenses are Tradesman Plumber-Limited, Journeyman Plumber, Master Plumber and Plumbing Inspector.
But the ladder is not the national rule — it is one pattern among several.
Five states license a journeyman and top the ladder with an individual contractor license instead of a master (Connecticut, Idaho, Indiana, Oklahoma, South Dakota).
Four have a journeyman-level license and no state master at all (Alaska, New Mexico, Oregon, Washington).
And four have no journeyman rung whatsoever: Delaware, Illinois, New Jersey and North Carolina — Illinois, for instance, has just two levels, the licensed apprentice plumber and the licensed plumber, while Delaware licenses only masters, New Jersey licenses masters and registers journeymen, and North Carolina splits technician classes from contractor classes.
Starting out?
Our plumbing apprentice guide covers the apprentice rung itself — the work, the pay and how apprenticeships are structured.
What can each level legally do?
The apprentice rung is supervised work, by design — the details of how much supervision are set where you work.
Delaware goes furthest: only a licensed master plumber may provide plumbing services there, and apprentices and journeymen work unlicensed under the supervision of a master who employs them or works full time for the same business.
The journeyman rung is the working license, and its scope is written state by state — what a journeyman may do unsupervised, and who pulls the permit for a job, are among the rules that differ across states.
One concrete marker of the rung's meaning: in Clark County, Nevada, journeyman is the minimum level for working without supervision.
For a deep dive on this rung, see our journeyman plumber guide.
The master rung carries the widest authority, and in many states it doubles as the business license: in Georgia, Maine, Kentucky, Delaware, Montana, Wisconsin, Texas, Louisiana, New Jersey, North Dakota, Connecticut and Rhode Island, the individual master (or equivalent) license is what lets a business contract — there is no separate state plumbing-contractor license.
In Connecticut, that top license is the individual P-1 Unlimited Plumbing Contractor rather than a "master".
The same holds in New York City and under Nebraska's city master licenses.
Elsewhere the contracting layer is separate: Ohio has no individual plumber license at all — the state licenses plumbing contractors, the businesses, only.
Our master plumber guide walks through that rung in detail.
One caution applies at every rung: never infer what a license permits from its title.
"Master" and "journeyman" do not mean the same scope in two different states, so read the rule, not the name.
Is plumbing licensed by the state or locally where you live?
Usually the state — but not everywhere.
As of September 29, 2026, seven states have no state plumber license: Florida, Kansas, Missouri, Nebraska, Nevada, New York and Wyoming.
There, cities and counties (or an industry board) do the licensing.
The local models differ in useful ways.
New York has no statewide plumber license; licenses are issued locally, and state law — General City Law Article 4, section 40-a — provides for examining boards of plumbers in cities.
Kansas City, Missouri issues Journeyman Plumber and Master Plumber certifications, required for anyone performing or supervising plumbing work in the city.
Nebraska is the sharpest version: the state itself requires anyone installing or repairing sanitary plumbing to be a master plumber licensed by the city or village nearest the job site, with employees licensed as journeymen by that same city or village.
And Nevada has no state journeyman or master license — in Clark County, plumbers carry an ID card from the Nevada Board of Plumbing Examiners, an industry-founded board that is not a state agency.
Practically, the issuer changes everything about your paperwork: where you apply, who tests you, whose records hold your license, and what happens when you move across a county line.
When you are unsure who licenses plumbers where you live, the local building department is the right first call.
Our state-by-state plumbing license guides are in the works; until they ship, treat the board or local office as the source of truth.
How many hours and which exams does each level take?
Start with the honest answer: there is no national number of hours.
Experience requirements, journeyman and master definitions, continuing-education hours and permit rules are set by the states individually — no federal source defines them.
Any single figure you see quoted as "the" plumbing license requirement is one jurisdiction's rule, not the country's.
For the apprenticeship stage, the U.S. Department of Labor recommends — but does not require — a minimum of 144 hours of related technical instruction per year of apprenticeship; each registered program's standards set the actual numbers.
For one concrete state example: New Hampshire's plumbing apprenticeship is 8,000 hours (about 4 years) of on-the-job training plus 144 hours of related classroom instruction per year.
That is New Hampshire's rule — not a national template.
Exams follow the same state-by-state pattern.
Where a state licenses both a journeyman and a master rung, each is typically tested separately — but exam structure is one of the board-by-board rules, and the states without those rungs, described above, don't follow the pattern.
A hands-on practical is the exception rather than the rule, but it exists: plumbing license exams with a practical component were found in Texas, Kentucky, Louisiana, Michigan, New Jersey (master), New Mexico and Utah, plus Montana's diagram-based practical and the local practicals in New York City and Omaha.
Texas shows how the pieces fit together: TSBPE written exams are delivered by Pearson VUE, and journeyman and tradesman candidates coming from apprentice — plus medical gas candidates — must also pass a hands-on practical at the board's Austin or Waco exam centre.
The figures above are examples — your state writes its own
Which extra credentials sit beside the license (backflow, med gas, gas)?
A certification is not a license — but the specialties that pay well often attach to one, either as endorsements printed on the license or as separate certificates the state requires you to hold alongside it.
Endorsements.
Texas's board offers three endorsements on its Journeyman, Master and Inspector licenses: Medical Gas Piping Installation, Multipurpose Residential Fire Protection Sprinkler Specialist, and Water Supply Protection Specialist — each renewed every three years.
Backflow.
Backflow prevention assembly testing is its own credential in a number of states: Texas (a TCEQ BPAT license), Arkansas (Assembly Testing Technician), Virginia (backflow prevention device worker), Wisconsin (Cross Connection Control Assembly Tester), Minnesota (testers need ASSE 5110) and Washington (the PL30 plumber specialty requires a state Department of Health tester certificate).
Louisiana and Texas also offer a Water Supply Protection Specialist endorsement for licensed plumbers.
What the work involves is covered in our backflow tester guide.
Medical gas.
Hospital oxygen and vacuum systems lean on the ASSE Series 6000 standards — the 2024 edition parallels NFPA 99-2024 and covers 6010 installers, 6020 inspectors, 6030 verifiers, 6035 bulk medical gas and cryogenic fluid central supply verifiers, 6040 maintenance personnel and more.
Some states wire the certification into licensing itself: in Kansas, medical gas piping may be installed only by a plumber licensed locally under the state's uniform standards — Kansas has no state-issued plumber license — who also holds the appropriate ASSE Series 6000 certification.
Gas.
Gas fitting often rides along with a plumbing license — but not always.
Standalone state gas-fitter credentials, separate from the plumber license, exist in Alabama, Alaska, Arkansas, the District of Columbia, Louisiana, Maine, Maryland, Massachusetts, New Hampshire, New Mexico, North Carolina, Utah, Vermont and Virginia, and Texas regulates LP-gas through the Railroad Commission.
Our gas fitter guide covers that trade.
How do plumbing licenses work state by state?
Cross-state research as of September 29, 2026 establishes six licensing patterns across the states:
| Licensing pattern | States (as of September 29, 2026) |
|---|---|
| Classic ladder — apprentice/trainee → journeyman → master (24) | Alabama, Arkansas, Colorado, District of Columbia, Georgia, Hawaii, Iowa, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Montana, New Hampshire, North Dakota, Rhode Island, Texas, Utah, Vermont, Virginia, West Virginia, Wisconsin |
| Journeyman license topped by an individual contractor license — no state "master" (5) | Connecticut, Idaho, Indiana, Oklahoma, South Dakota |
| Journeyman-level license, no state master (4) | Alaska, New Mexico, Oregon, Washington |
| Statewide license with no journeyman rung (4) | Delaware, Illinois, New Jersey, North Carolina |
| No state plumber license — cities, counties or an industry board (7) | Florida, Kansas, Missouri, Nebraska, Nevada, New York, Wyoming |
| No individual plumber license — the state licenses plumbing contractors only (1) | Ohio |
The table counts only what verified sources support.
Other states could not be confirmed either way, and the research says so plainly: Tennessee appears to have only a limited state plumber credential, with journeyman and master tiers handled locally; Pennsylvania appears to have no state plumber license, with cities and counties licensing instead; and Arizona, California, Mississippi and South Carolina appear to license plumbing contractors only, with no individual worker license — but none of that is verified, so none of it is counted above.
If you live in one of those states, treat it as an open question for the state agency, not an answer.
Two more wrinkles matter when you compare states.
First, in the dozen-plus jurisdictions listed above, the top individual license — a master, or in Connecticut the individual P-1 Unlimited Plumbing Contractor — is the business license: a plumber there can hold it and contract under it without a separate state contractor license.
Second, titles travel badly: a "journeyman" license in one state and the next can sit behind different scopes, hour rules and permit rights.
Check the rule where you plan to work, not the word on the license.
Career information, not legal advice. Licensing requirements change; confirm the current rules with your state licensing board, or the city or county office where licensing is local, before you apply for a license or bid work.