You become a plumber by following one well-worn road: finish high school or a GED, get hired as a helper or a registered apprentice, log about 2,000 hours of paid on-the-job training a year for four or five years, and then pass the journeyman exam where you live.
The fine print at every step is set by states and cities, not by any national rule.
This guide walks the road in order and tells you who sets each requirement.
What are the requirements to become a plumber?
There is no national plumber license, so the honest answer starts with who makes the rules: state licensing boards license plumbers in most but not all states, and in the states that do not, cities and counties do.
What holds everywhere is the shape of the route.
A high school diploma or equivalent is the typical educational requirement, the trade itself is learned in paid, supervised on-the-job training, and a license is issued by the authority where you work — never by the apprenticeship program itself.
The fixed requirements at the entry are modest.
BLS says a high school diploma or equivalent is typically required to become a plumber, and a registered apprentice must be at least 16 years old under the federal rulebook, unless a higher minimum is set by law.
Everything after that is hours, classroom instruction, and your local license rules.
The five steps look like this:
Finish high school or a GED
BLS names a high school diploma or equivalent as the typical requirement; some plumbers first attend a vocational-technical school.Get hired as a helper or apprentice
Earn while you learn — as a plumber's helper or in a registered apprenticeship run by a contractor or a union.Log the hours and the classroom time
About 2,000 hours of paid on-the-job training a year, plus technical instruction, for four or five years.Pass the journeyman exam where you live
Licensing is state and local: the board — or the city or county — sets the requirements.Advance to master or specialize
The senior rung, or a specialty such as pipefitting and steamfitting inside the same federal occupation.
For what the job involves at each rung — the duties, the settings, the pay — see our plumber career guide.
The rest of this article stays on the road itself.
Licensing rules are local — confirm before you act
Step 1: finish high school or GED (the math you need)
Start with the credential BLS names: a high school diploma or equivalent is typically required to become a plumber, and some plumbers attend a vocational-technical school before on-the-job training begins.
A stand-alone plumbing school program is one way to prepare, but it is not the gate — the classroom hours that count come with the apprenticeship, covered in step 3.
The math is shop math, and it shows up straight in the code book.
Under the 2024 International Plumbing Code, Table 704.1 sets the minimum slope for horizontal drainage pipe at 1/4 inch per foot for pipe 2-1/2 inches or smaller, 1/8 inch per foot for 3- to 6-inch pipe, and 1/16 inch per foot for 8-inch and larger — fractions you will convert, add, and cut pipe to all day.
Offsets compress trigonometry into multipliers: travel equals the offset times 1.414 for 45-degree fittings, 2.000 for 30 degrees, 1.155 for 60, 2.613 for 22-1/2, and 5.126 for 11-1/4.
These are the model code's minimums and generic fitting math — the plumbing code where you work governs.
Apprenticeship classrooms teach this directly: first-year apprentices at Plumbers Local 1 in New York City, for example, work from UA 1300 Related Mathematics alongside texts on tools, plan reading, drainage systems, and water supply.
If your fraction and geometry work is rusty, a GED prep course or a community-college refresher covers what the shop will ask of you.
Step 2: get hired as a helper or apprentice (union vs non-union routes)
Two doors lead into paid plumbing work, and both count toward the license.
The first is a helper job.
BLS counts Helpers—Pipelayers, Plumbers, Pipefitters, and Steamfitters (SOC 47-3015) as their own occupation, with 44,330 wage-and-salary jobs nationally in May 2025 and a median wage of $20.36 an hour, or $42,360 a year — paid work on a plumbing crew from day one.
The second door is a registered apprenticeship: a formal program registered with the U.S. Department of Labor's Office of Apprenticeship or a recognized State Apprenticeship Agency, which pairs your paid work with structured classroom instruction and ends in a completion certificate.
The union route runs through the United Association (UA), which says it represents about 409,000 plumbers, pipefitters, sprinkler fitters, HVACR service technicians, welders, and related trades in North America.
UA apprenticeships are registered with the Department of Labor, typically last five years, and cover plumbing, pipefitting, HVACR, welding, and fire protection; they include 2,000 hours of paid on-the-job training per year plus 216 hours of related classroom instruction.
Each local union runs its own intake — dues, application windows, and waiting lists vary local by local — so what your nearby local requires is a question for that local.
The non-union route is hiring on directly with an open-shop (merit-shop) contractor.
The Associated Builders and Contractors describes itself as founded on the merit shop philosophy and reports more than 24,000 members, and the Plumbing-Heating-Cooling Contractors Association offers apprenticeship content through an online learning academy.
Whether a given contractor sponsors a registered program or hires helpers first and supports registration later is one of the first questions to ask in the interview.
Which door is faster depends entirely on what is hiring where you live.
Our plumbing apprentice guide covers the apprenticeship route in depth.
Step 3: log apprenticeship hours and classroom training
Most plumbers, pipefitters, and steamfitters learn the trade through a 4- or 5-year apprenticeship, with about 2,000 hours of paid on-the-job training each year plus technical instruction, per BLS.
The federal rulebook for registered programs sets the floor, not the finish line: an apprenticeable occupation must require at least 2,000 hours of on-the-job learning, a registered apprentice must be at least 16 unless the law sets more, and there is no federal maximum age — 29 CFR part 30 prohibits discrimination against apprentices and applicants aged 40 or older in registered programs.
On the classroom side, the Department of Labor recommends — but does not require — a minimum of 144 hours of related technical instruction per year of apprenticeship; some states mandate their own classroom hours, so 144 is a benchmark, not a law.
The other terms live in each program's standards.
Programs must pay a progressively increasing wage tied to skill, but the federal rule sets no percentage steps — the raises are in the program's own standards.
Programs must state a numeric apprentice-to-journeyworker ratio, with no federal number.
The probationary period may not exceed 25 percent of the program length or 1 year, whichever is shorter, and it counts toward completion.
Programs may be time-based, competency-based, or a hybrid of both.
Finish, and the registration agency — DOL's Office of Apprenticeship or the state apprenticeship agency — issues you a completion certificate.
That certificate is portable proof that you completed a registered program.
It is not a license: the license comes from the state board or the city, which is the next step.
Step 4: pass the journeyman plumber exam
The journeyman rung is where the road forks by state.
Whether there is a journeyman license at all — and what the exam covers — is decided by the board that licenses where you live, and in some states the city or county licenses where the state does not.
The full state-by-state picture of plumbing license requirements is on our licensing page; this section is the journeyman rung itself.
As of September 2026, 24 states run the classic statewide apprentice → journeyman → master ladder.
Five — Connecticut, Idaho, Indiana, Oklahoma, and South Dakota — issue a journeyman license but top the individual ladder at a plumbing contractor license instead of a master title.
Four — Alaska, New Mexico, Oregon, and Washington — license at the journeyman level with no state master license.
Four — Delaware, Illinois, New Jersey, and North Carolina — have no journeyman rung at all: Illinois licenses apprentice then plumber, Delaware licenses masters, New Jersey licenses masters while registering journeymen, and North Carolina uses technician and contractor classes.
And seven — Florida, Kansas, Missouri, Nebraska, Nevada, New York, and Wyoming — have no general state plumber license; cities, counties, or an industry board do the licensing instead.
Where a journeyman license exists, the exam is mostly a written test of code and trade knowledge; hands-on practical portions are the exception.
Plumbing license exams with a practical element were found in Texas, Kentucky, Louisiana, Michigan, New Jersey (for the master license), New Mexico, and Utah, plus Montana's diagram-based practical and local practicals in New York City and Omaha.
Whatever the format, the licensing authority writes the eligibility rules and the content — its candidate handbook is the syllabus.
Our journeyman plumber guide covers this rung in detail.
Step 5: advance to master plumber or specialize
The master license is the trade's senior individual credential, and what it unlocks is largely about contracting.
In 12 states — 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 for plumbing work, with no separate state plumbing-contractor license; the same holds in New York City and under Nebraska's city master licenses.
In the nine states with no master title — the five contractor-topped states plus the four journeyman-only states — the individual ladder tops out elsewhere, and contracting runs through a separate contractor license where the state issues one.
Specializing is the other direction.
Federally, the occupation plumbers belong to also counts pipefitters and steamfitters — O*NET merged the old Plumber and the Pipe Fitters and Steamfitters codes into one occupation, 47-2152.00, and the old codes are "no longer in use".
What that classification does not tell you is whether a licensing board or program credits hours across those trades — that, like everything in steps 4 and 5, is the local board's call.
The pay ladder climbs with the license ladder: our plumber salary page has the state-by-state figures, and our master plumber guide covers the senior rung in detail.
Can you become a plumber without an apprenticeship?
Yes — a registered apprenticeship is the structured route, not the only door.
Helpers learn on real job sites without one, and whether documented work experience can substitute for a registered program when you apply for a journeyman license is decided jurisdiction by jurisdiction.
Oklahoma shows the pattern: journeyman exam applicants there must be 18 and have three years of plumbing experience while employed by a licensed plumbing contractor — and approved school hours can substitute, with a 1,000-hour approved program counting for two years.
The trade-offs run both ways.
A registered program pays a progressive wage on a published schedule, sequences what you learn, and ends in a completion certificate that is portable; a license, by contrast, is not.
Going unregistered means tracking your own hours against the licensing board's rules from day one — so before you take a helper job outside a registered program, ask the board that licenses you whether documented experience qualifies, and how it must be documented.
How to find your first plumbing job
Entry-level plumbing work concentrates with contractors, and mostly in the biggest states.
Texas (7,210), New York (4,840), and Florida (4,500) held the most helper jobs in May 2025, and building equipment contractors employed 39,160 of the nation's 44,330 helper jobs.
That makes the search straightforward in shape: the employers to approach are plumbing and HVAC contractors.
Run it through three channels.
Apply directly to contractors for entry-level plumbing jobs — many hire helpers continuously.
Ask each one whether it sponsors a registered apprenticeship or will support your registration once you are on board.
And for the union route, contact your UA local about its apprenticeship intake, remembering that every local sets its own process and requirements.
HVACHires lists plumbing jobs straight from HVAC and plumbing contractors hiring now: browse plumber jobs to see what is open near you.
How to start a plumbing career: step 1 — get into an apprenticeship (or helper job)
Pick your door: a union apprenticeship through a UA local, a registered program with an open-shop or independent contractor, or a helper job to start earning immediately.
The fixed requirements are modest — 16 is the federal minimum age for registered apprentices, and a high school diploma or GED is the typical educational requirement.
Everything else is set by the program or the local you apply to.
How to start a plumbing career: step 2 — log your hours and classroom training
Then log the road: four or five years of about 2,000 hours of paid on-the-job training a year, plus the classroom instruction your program or state requires.
Completing a registered program earns a completion certificate; the journeyman license comes from the board — or the city or county — that licenses where you live.
Pass its exam, and the ladder's next rung is yours.
Career information, not legal or licensing advice. Licensing requirements are set by state boards and, in some states, by cities and counties — confirm the current rules with your state licensing board, or the city or county where licensing is local, before you act on anything here.