Awaiting expert review. This page covers safety or regulatory rules that change over time. It is kept out of search results until a qualified reviewer has checked it; the sources below are dated so you can verify each point.
Quick answer
A licensed master plumber is a plumber who has passed a state or local master-level exam after years of licensed journeyman work, and who may plan plumbing work, supervise journeymen and apprentices, and, in many states, run a plumbing business or pull permits.
There is no national plumbing license. Each state, and sometimes a city, sets its own titles, experience hours and exam. Titles and the rights they carry differ by state.
Quick facts
The key facts about Licensed Master Plumber, with sources:
- Texas
- Journeyman to master experience cut from four years to two, effective September 1, 2025 2
- Minnesota
- Journeyworker exam after four years and at least 7,000 hours; master has five or more years 3
- Massachusetts
- Master: at least one year as journeyman, 100 hours advanced theory, master exam 4
- Washington
- Journey level certificate after four years under a certified journey level plumber 5
- Continuing education (Texas)
- Six hours to renew 1
Key takeaways
- A master plumber license is the senior plumbing license in states that use the title; it is earned after journeyman-level experience and an exam.
- Requirements are set state by state; Texas, Minnesota and Massachusetts each count experience differently.
- In many states a master supervises journeymen and apprentices, and only licensed plumbers may get permits.
- Some states use other titles, such as journey level, journeyworker or plumbing contractor, so “master” is not universal.
- Always check a license on the state board’s lookup before hiring.
What a master plumber license means, and how it differs from journeyman
Plumbing licenses usually come in steps. An apprentice learns under supervision. A journeyman (Minnesota says journeyworker) has finished years of supervised work and passed an exam, and can work on their own. A master has more experience on top of that and has passed a harder exam.
Massachusetts puts it plainly.
Its Board of State Examiners of Plumbers and Gas Fitters says a master plumber has worked at least one year as a journeyman, completed 100 hours of advanced plumbing theory, and passed the master exam; a master may work as an individual, firm or corporation and may employ journeymen and apprentices 4.
The rights attached to the license vary. In Minnesota, journeyworkers must work under the direction of a master plumber in any city with a population over 5,000 3. In Massachusetts, plumbing permits are issued only to licensed plumbers 4.
Master plumber vs plumbing contractor
A master license is about the person’s skill and experience. A contractor license or registration is about the business: bonding, insurance and who is responsible for the work. Some states require both; Washington defines a “plumbing contractor” separately from a “journey level plumber” 6.
How a plumber becomes a master
The path below is the common shape; the numbers are from the state sources cited and differ elsewhere.
- Register as an apprentice. Massachusetts registers apprentices, who work under the direct supervision of a master or journeyman 4.
- Log supervised experience. Minnesota apprentices may sit for the journeyworker exam after four years and at least 7,000 hours 3. Washington requires four or more years under a certified journey level plumber for its journey level certificate 5. Massachusetts requires three years as an apprentice plus 300 hours of theory 4.
- Pass the journeyman exam. Every state source we reviewed requires an exam 134.
- Work as a journeyman. Texas reduced the journeyman experience needed for the master exam from four years to two (the old rule also allowed one year with a U.S. Department of Labor program certificate), effective September 1, 2025 2. Massachusetts requires at least one year 4.
- Pass the master exam. Texas says applicants must meet eligibility, pass the exam and pay a fee 1.
- Keep it current. Texas requires six hours of continuing education to renew 1.
- ApprenticeRegistered, supervised
- Journeyman examAfter years of logged work
- JourneymanWorks independently
- Master examAfter more licensed experience
- MasterSupervises; may run a business
The first rung is where states differ most. The chart compares the supervised time each state asks for before the journeyman exam; Massachusetts asks for less time but adds classroom hours.
Which plumbing licenses Texas, Minnesota and Massachusetts issue
| State | License types named by the board | Note |
|---|---|---|
| Texas (TSBPE) | Tradesman Plumber-Limited, Journeyman Plumber, Master Plumber, Plumbing Inspector; Responsible Master Plumber also listed 1 | Journeyman and master may be held at once 1 |
| Minnesota (DLI) | Journeyworker, master, restricted journeyworker, restricted master 3 | Restricted licenses required experience documented before October 1, 2008 3 |
| Massachusetts (Board of State Examiners) | Journeyman and master plumbers; journeyman and master gas fitters; LP installers 4 | A licensed plumber may do gas fitting; a gas fitter may not do plumbing 4 |
Example: the experience behind a master license in three states
A side-by-side of what each state’s source says it takes. Hours and years are as published; the comparison is ours.
| Step | Texas | Minnesota | Massachusetts |
|---|---|---|---|
| Before journeyman exam | Not stated on the license-types page 1 | Four years, at least 7,000 hours 3 | Three years as apprentice, 300 hours theory 4 |
| Journeyman time before master | Two years from September 1, 2025 (was four) 2 | Master described as five or more years of practical experience 3 | At least one year, plus 100 hours advanced theory 4 |
| Exam | Yes 1 | Yes, for journeyworker 3 | Yes 4 |
| Renewal | Six hours of continuing education 1 | License carried on site 3 | License shown on request 4 |
Journeyman
- Passed the journeyman exam
- Works independently on plumbing
- May supervise apprentices in some states
- In Minnesota, works under a master in cities over 5,000
Master
- More licensed experience plus a master exam
- Plans and supervises work
- May employ journeymen and apprentices (Massachusetts)
- Often tied to running the business or pulling permits
The same title can mean different training. A master in one state is not automatically licensed in another; reciprocity rules vary.
Where a plumber’s license number should appear
On ads and trucks. Massachusetts requires a master or journeyman plumber’s license type and number on any sign, listing or ad 4.
On the permit. In Massachusetts, the plumber must sign, under penalties of perjury, that they carry liability insurance, or present a waiver signed by the homeowner 4. See plumbing permit.
On the job site. Minnesota says licenses must be carried at all times on a work site 3.
On a quote. Look for the license number and the name of the licensed person responsible for the job.
What a master license tells you, and what it does not
It tells you
It does not tell you
- Whether this company is good at your kind of job.
- Whether the master will be on your job or just supervising.
- Whether insurance is current today; ask for proof.
- Price or schedule.
Why the master title alone is not enough to hire on
A license is a floor, not a guarantee: it proves training and an exam at one point in time, but it says little about whether the firm answers calls, cleans up, or has done your kind of job. Many crews are led by journeymen working under a master’s license, which can be fine and legal.
Titles also confuse. Washington’s plumbing law defines a journey level plumber and a plumbing contractor in its definitions section, without a master title there 6. A firm in that state can be properly licensed without anyone called “master.” Ask what your state requires, not what the ad says.
How licensing affects what you pay
We do not print prices; fair numbers need dated local quotes.
Licensing, insurance, bonding and continuing education are real business costs, and they show up in rates. So does the supervision structure: work done by a journeyman under a master may be billed differently from work done by the master. What you pay is driven more by the job, access and materials than by the title.
Our plumbing cost guide explains how quotes are built. Unlicensed work can cost more later if it fails inspection or voids insurance coverage.
How to check a plumber’s license
- Get the license number and name. In Massachusetts it must be on ads 4; elsewhere, ask.
- Use the state lookup. Minnesota DLI links a license lookup from its consumer page 3. Massachusetts offers verification of licensure, years licensed and disciplinary history 4. For Texas, start at the TSBPE site.
- Check the type. Make sure the license covers the work: plumbing, not only gas fitting; full license, not restricted where that matters 34.
- Check the business. Where the state licenses contractors separately, confirm that too 6.
- Ask for insurance proof. Massachusetts permits require sworn insurance or a homeowner waiver 4.
- Confirm the permit. The licensed plumber, not you, should pull it where the state requires 4.
Unlicensed work can be dangerous
Massachusetts warns that untrained work can create cross-connections that contaminate water supplies and that badly installed temperature and pressure relief valves can cause serious explosions 4. Gas piping, water heater relief valves and backflow devices are licensed-pro work. If you smell gas, leave and call the gas utility or 911.
How a plumbing license stays current
- Texas licensees complete six hours of continuing education to renew 1.
- Texas sets a first journeyman expiration 6 to 18 months after the exam, and matches a master’s expiration to the journeyman’s 1.
- Minnesota licenses must be renewed and carried on the job site 3.
- Massachusetts masters must keep a regular place of business with the license displayed 4.
- Recheck a license before each big job; status can change.
Save the lookup page
Take a screenshot of the license lookup result with the date. If a dispute arises later, you have proof of what the state showed when you hired.
Which licensing red flags to watch for when hiring
- No license number on the quote, truck or ad, in a state that requires it 4.
- A license number that does not match the name or company on the lookup.
- A request that you pull the permit yourself for work the plumber is doing.
- No proof of insurance, or a request that you sign an insurance waiver 4.
- Cash-only pricing with no written scope.
See how to choose a plumber for the full checklist, and how we vet plumbers for what we check before listing a business. HyrePlumber does not employ or license plumbers; the state does.
Which state boards regulate plumbers
Texas. The Texas State Board of Plumbing Examiners issues Tradesman Plumber-Limited, Journeyman, Master and Plumbing Inspector licenses and requires six hours of continuing education to renew 1.
Its June 23, 2025 notice says the Legislature cut the journeyman experience needed for the master exam from four years to two, effective September 1, 2025 2.
Minnesota. The Department of Labor and Industry licenses journeyworker and master plumbers; journeyworkers must work under a master in cities over 5,000, and licensed contractors carry a surety bond and liability insurance 3.
Massachusetts. The Board of State Examiners of Plumbers and Gas Fitters licenses journeyman and master plumbers, writes the uniform state plumbing code, and says only a licensed master or journeyman, with a local permit, may do plumbing work at a home or business 4.
Washington. RCW 18.106.040 sets four or more years under a certified journey level plumber for the journey level exam 5; RCW 18.106.010 defines journey level plumbers and plumbing contractors 6.
Other states and many cities have their own rules. Check your state board before hiring or starting work.
How master plumber compares with apprentice, journeyman and contractor
| Title | What it usually means | Example source |
|---|---|---|
| Apprentice | Registered learner under supervision | Massachusetts 4 |
| Journeyman / journeyworker / journey level | Licensed to do plumbing work independently | Minnesota, Washington 35 |
| Master plumber | Senior license; supervises and may employ | Massachusetts, Texas 41 |
| Restricted master | Master with limits on where it applies | Minnesota: design only in cities under 5,000 3 |
| Plumbing contractor | The business that offers plumbing work | Washington 6 |
Which plumbing license beliefs are wrong
- Myth There is a national master plumber license.
- Reality Licensing is state by state; the boards cited here each set their own rules 134.
- Myth A journeyman cannot work alone.
- Reality Minnesota says a licensed journeyworker may work without on-site supervision, though under a master’s direction in larger cities 3.
- Myth Every state has a master license.
- Reality Washington’s definitions section names journey level plumbers and plumbing contractors, not masters 6.
- Myth The master is on every job.
- Reality A master often supervises journeymen and apprentices doing the work 4.
- Myth Requirements never change.
- Reality Texas halved its journeyman-to-master experience rule in 2025 2.
Why your state sets the licensing rules
Licensing is the clearest state variable in plumbing. Texas changed its master experience rule on September 1, 2025 2. Minnesota ties supervision to city population 3.
Massachusetts lets only licensed plumbers obtain permits and requires sworn insurance or a homeowner waiver on each permit 4. Washington builds its system around journey level certificates and contractor registration 56.
Before hiring, look up your own state’s board and its license search.
When the license matters to your hire
It matters most on permitted work: new lines, water heaters, repiping, sewer and gas. Those jobs need a properly licensed person and, often, a permit in their name. For small repairs, a licensed journeyman under a master can be the right fit.
Before you sign, verify the license on the state site, confirm insurance, and ask who will be on site and who is responsible for the permit.
- If Permit-level job
- Then Licensed plumber who will pull the permit 4
- If Gas line or water heater
- Then Licensed pro only; ask about gas qualifications
- If Small repair
- Then Licensed journeyman or master is usually fine
- If License not on lookup
- Then Do not hire until it is resolved
- If Moved from another state
- Then Check that the license is valid in yours
Source: [4]
Questions about Licensed Master Plumber
What is the difference between a master plumber and a journeyman?
A journeyman has passed the first licensing exam after years of supervised work and can do plumbing independently. A master has more licensed experience and has passed a master exam. In Massachusetts a master may employ journeymen and apprentices; in Minnesota journeyworkers must work under a master in cities over 5,000.
How long does it take to become a master plumber?
Several years, and it depends on the state. Minnesota apprentices can take the journeyworker exam after four years and 7,000 hours, and it describes masters as having five or more years.
Texas requires two years as a journeyman before the master exam since September 1, 2025. Massachusetts requires one year as a journeyman plus 100 hours of theory.
Do I need a master plumber or is a journeyman enough?
For most repairs, a licensed journeyman working for a properly licensed business is fine. Permitted work may need a license holder who can pull the permit; in Massachusetts permits go only to licensed plumbers. Ask who is responsible for the permit and verify both people on the state lookup.
How do I check if a plumber is licensed?
Use your state board’s online license search with the plumber’s name or number. Minnesota DLI links a lookup on its consumer page, Massachusetts offers verification of license, years licensed and disciplinary history. For Texas, start at the TSBPE website. Confirm the license type covers plumbing and the status is active.
Is a master plumber license valid in every state?
No. Each state issues its own licenses, and reciprocity agreements vary. A master licensed in one state usually must apply, and sometimes test, to work in another. Check the board in the state where the work is being done.
Can a master plumber do gas work?
Often, but it depends on the state. Massachusetts says a licensed master or journeyman plumber may do the work of a gas fitter, while a licensed gas fitter may not do plumbing. Other states license gas work separately. Ask about gas qualifications before hiring for a gas line.
Can a homeowner do their own plumbing?
It depends on the state and city. Massachusetts law allows only licensed plumbers to install or repair plumbing, except minor repairs such as fixing a leaky faucet or clearing a blocked drain. Some other states allow owners to work on their own homes with a permit. Check with your local building department first.
What is a Responsible Master Plumber in Texas?
Texas TSBPE lists Responsible Master Plumber as its own category next to the master license. The board page we reviewed names the category but does not set out its requirements, so we do not describe them here. Check TSBPE’s Responsible Master Plumber page or call the board for the current rules before relying on it.
Does a master plumber need insurance?
Rules vary. Minnesota says licensed plumbing contractors carry a surety bond and liability insurance. In Massachusetts, a plumber must swear on each permit application that they carry liability insurance, or the homeowner must sign a waiver. Always ask for a current certificate before work starts.
Sources
- Texas State Board of Plumbing Examiners, License Types, retrieved .
- Texas State Board of Plumbing Examiners, Important Notice: Upcoming Change to Master Plumber Requirements (June 23, 2025), retrieved .
- Minnesota Department of Labor and Industry, Choosing a plumber, retrieved .
- Massachusetts Board of State Examiners of Plumbers and Gas Fitters, Plumbers and Gas Fitters Consumer Fact Sheet (copy hosted by the Town of Hamilton, MA), retrieved .
- Washington State, RCW 18.106.040 Examinations, eligibility requirements, retrieved .
- Washington State, RCW 18.106.010 Definitions, retrieved .
Expert review
Written by the HyrePlumber Research team. Not yet reviewed by an outside expert. We say so rather than imply a review that has not happened; see our editorial policy.
How the numbers were checked: Held under G-REV until a licensed plumber signs.
Every licensing rule is attributed to the state body that publishes it: Texas TSBPE (license types and its June 2025 notice), Minnesota DLI (consumer page), the Massachusetts Board (consumer fact sheet; mass.gov blocked automated retrieval, so a town-hosted copy is cited) and Washington RCW 18.106.
No state’s rule is generalized to others. The Massachusetts master theory requirement is given as 100 hours per the Board’s fact sheet; some third-party summaries cite a different figure from 248 CMR 11.00, which we could not load.
California and other states are not described because their board pages could not be retrieved. HyrePlumber does not employ or license plumbers. No prices are given.
Suggest a correction. We fix errors and say what changed.