Plumbing License North Dakota: Four Separate Ladders and the 30-Day Rule That Voids a Year (2026)

North Dakota does not have "a plumbing license." It has four separate licensing tracks, and the one you need depends on which side of the building's foundation wall you are working on.

The North Dakota State Plumbing Board runs all four. There is the plumber ladder, apprentice, journeyman, master. There is a completely separate Sewer and Water ladder, apprentice, installer, contractor, for the pipe running from the building out to the public main. There is a Water Conditioning ladder. And there is a Certified Backflow Assembly Tester credential sitting off to the side.

Most contractors coming into North Dakota assume the master plumber license covers all of it. It covers more than you would expect, and less than you might hope, and the difference is worth real money on a bid.

This guide walks the whole structure with the Board's own published numbers: the hours, the exam fees, the renewal fees, the supervision rules, the waiting periods after a failed exam, and the one registration deadline that quietly voids a year of apprenticeship if you miss it.

New to licensing in North Dakota? Start with the North Dakota contractor license requirements, and for every other state see how to get a contractor license in each state.

The one deadline that costs people a year

Start here, because it is the single most expensive mistake in North Dakota plumbing licensure and almost nobody writes about it.

An apprentice plumber must be registered with the Board within thirty days of starting work. Not eventually. Not before you sit for the journeyman exam. Within thirty days of the day you start.

The Board is explicit about the consequence: "Hours worked after the thirty (30) days without being registered will not be counted towards the apprenticeship and is in violation of State Law."

Read that carefully. It is not a late fee. The hours do not count. If a shop puts a new hire on the truck in March and gets around to the paperwork in September, that hire has burned roughly six months of a four-year clock and the shop has committed a statutory violation on top of it.

For a company running an apprentice program, this is a payroll-onboarding item, not a licensing item. It belongs on the first-week checklist next to the I-9.

The plumber ladder

North Dakota licenses plumbers in three grades, and the apprentice grade is itself split into five annual steps that each carry their own renewal fee.

Apprentice plumber. Must be eighteen. Must register within thirty days of starting employment, as above. The Board tracks apprentices by year, first year through fifth year, and the renewal fee climbs with the year. The administrative rule sets the apprentice term at four years, not less than 1,900 hours per year, for a total of not less than 7,600 hours.

Supervision is where the apprentice years actually differ from one another. Per the Board: first, second, and third year apprentices must work under the direct supervision of a master or journeyman plumber. Fourth and fifth year apprentices may work by themselves.

That is an unusually generous rule, and it is a real scheduling asset. In a lot of states an apprentice never works unaccompanied. In North Dakota a fourth-year apprentice is a body you can send to a service call alone. If you are staffing a North Dakota branch, the fourth-year mark is the point where an apprentice stops being a passenger and starts being a truck.

There is also a supervision cap that shows up nowhere in the aggregator write-ups. The administrative rule states there shall not be more than five plumber's apprentices under the immediate and personal supervision of either a master plumber or journeyman plumber on any installation, alteration, or repair project. If you are planning crew ratios on a large job, that is a hard ceiling.

Hour credit from outside the ladder. The Board may grant hourly credit toward a term of apprenticeship when an applicant furnishes proof of previous practical experience in the trade. Separately, graduates of at least a nine-month, 1,020-hour plumbing course at an accredited school may be granted credit, and the rule scales the credit by grade average: A average, two hours of credit per course hour; B average, one and three-quarter hours; C average, one and one-half hours; D average, one hour. That is a rare and specific rule. Your GPA, not merely your completion, determines how much of the ladder the schooling buys you.

Journeyman plumber. Eligibility requires proof of four (4) years AND seven thousand six hundred (7,600) hours working in the trade under the supervision of a licensed master plumber.

Note the conjunction. It is and, not or. Seven thousand six hundred hours compressed into two-and-a-half years of heavy overtime does not qualify you, the four calendar years still have to elapse. Contractors who run their crews hard sometimes assume hours are the only gate. In North Dakota they are one of two gates.

Note also the supervisor. The hours must be under a licensed master plumber. Hours under a journeyman do not satisfy the requirement as the Board words it.

There is one alternate route, and it is narrow. Applicants working the plumbing trade in localities where state licenses are not required, who have five years of experience (1,900 hours per year, 9,500 hours total) and who furnish four affidavits verifying those years, may apply for a journeyman examination screening test, an oral and written test given by the Board plus a state inspector's report on an installation the applicant actually built. It is a longer road with an extra gate, not a shortcut.

Master plumber. Eligibility requires the applicant to be twenty-one (21) years of age and to have two (2) years AND three thousand four hundred (3,400) hours of experience as a licensed journeyman plumber.

Again and, again two gates. And note the age floor applies at the master level specifically, eighteen gets you an apprentice card, twenty-one is the earliest a master license is possible.

Run the arithmetic on a straight-line career and North Dakota's fastest realistic path from zero to master plumber is six years: four as a registered apprentice, two as a licensed journeyman. There is no hour-stacking shortcut around the calendar.

Exam fees, passing grades, and the six-month penalty box

Both plumber exams cost the same:

• Master plumber exam, $50.00
• Journeyman plumber exam, $50.00

Those are the Board's own published exam fees, and the administrative rule confirms the same fifty-dollar figure as both the application fee and the per-examination fee. They are notably cheap. Several states route their plumbing exams through a national testing vendor at three to five times that price; North Dakota administers its own and charges fifty dollars.

The rule also publishes the cut scores, which most state boards do not: the passing grade for a master plumber is eighty percent, and for a journeyman plumber seventy percent. The exam itself is described as questions on the basic principles of plumbing and the plumbing code, plus a drawing component in which the applicant lays out stacks, wastes and vents and inserts minimum pipe sizes.

The penalty for failing is expensive in the only currency that matters:

"A plumber who has written and failed the exam will have to wait a six (6) month period before rewriting the exam."

Six months. Not thirty days, not ninety. If a journeyman candidate fails in February, the next attempt is in August, and a promotion, a raise, and possibly a job offer all slide half a year to the right.

This is worth stating plainly because it changes the economics of preparation. In a state with a thirty-day retest window, sitting early and finding out where you stand is a defensible strategy. In North Dakota it is not. The cost of a failed attempt is not the fifty dollars, it is the two quarters.

There is a second clock most people miss. Under the administrative rule, an approved application expires and is canceled after six months if the applicant fails to appear for examination within that period. Get approved, skip two Board exam dates, and you are re-applying and paying again.

Exams are given on a published schedule set by the Board each year rather than on demand, so the retest date is also constrained by when the Board next offers the exam, the six months is a floor, not a ceiling.

Fees, cut scores and waiting periods on this page are set by the North Dakota State Plumbing Board and are subject to change. Verify current amounts and the current exam calendar with the Board before relying on them.

Renewal fees, grade by grade

North Dakota renews plumbing licenses annually, and the fee tracks the grade, including each individual apprentice year, which is unusual. Most states charge one apprentice fee regardless of seniority.

Plumbing renewal fees published by the Board:

• Master Plumber, $200.00
• Journeyman Plumber, $100.00
• 5th Year Apprentice Plumber, $75.00
• 4th Year Apprentice Plumber, $50.00
• 3rd Year Apprentice Plumber, $40.00
• 2nd Year Apprentice Plumber, $30.00
• 1st Year Apprentice Plumber, $20.00

For a shop with a full apprentice bench, that graduated structure matters at budget time, a five-apprentice crew spread across the year-grades is a materially different renewal line than five apprentices at a flat rate.

Two further rules govern what happens when a renewal slips. The late renewal fee is $50.00. And under the administrative rule, no license need be renewed by the Board later than one year after its expiration, past that point the Board may, at its discretion, require the holder to sit a new examination. A lapse of thirteen months is not a paperwork problem; it is potentially a re-testing problem, with the six-month failure window attached to it.

One convenience worth knowing: a master plumber may renew the journeyman certificate and then, during the same year, reinstate the master certificate by paying the difference between the $100 journeyman renewal and the $200 master renewal.

Continuing education: a two-to-four hour requirement

North Dakota does require continuing education, and the requirement is modest by national standards.

Per the Board: journeyman and master plumbers must complete at least two (2) to four (4) credit hours within a two (2) year period.

The Board publishes its own CE session schedule, a correspondence course option, and approved online courses, and it maintains standing CE modules on specific technical subjects, horizontal wet venting, boiler installations and inspections, and alternate island sink installation among them. Apprentices are not named in the CE requirement; it attaches to the two licensed grades.

Two to four hours per biennium is light. For comparison, states that require fifteen or more hours per cycle are common. If you are building a compliance calendar across several states, North Dakota is the one you will be tempted to forget, and forgetting it is how a license lapses.

The Sewer and Water track is a different license with different rules

This is the part most out-of-state contractors get wrong, and it is the part that shows up as a stop-work order.

Anyone installing sewer and water in North Dakota must be licensed with the State Plumbing Board, except for master plumbers licensed in North Dakota, who are covered. So a North Dakota master plumber can do the sewer and water work. Everybody else needs the separate credential.

The Sewer and Water ladder has its own three grades and its own hour requirements, and they are not the plumber numbers:

• Sewer and Water Apprentice, entry grade.
• Sewer and Water Installer, requires two (2) years and three thousand four hundred (3,400) hours installing sewer and water under the supervision of a licensed Sewer and Water Contractor.
• Sewer and Water Contractor, requires one (1) year and one thousand seven hundred (1,700) hours installing sewer and water as a licensed Installer under a licensed Sewer and Water Contractor.

Three years total from apprentice to contractor, against six years on the plumber ladder. It is a genuinely faster route to a license that lets you run work.

And the exams are free:

• Sewer and Water Contractor exam, $0.00
• Sewer and Water Installer exam, $0.00

The failed-exam waiting period is also different. Where a failed plumber exam costs you six months, a failed Sewer and Water exam costs you three (3) months. Same board, same building, half the penalty. Do not carry the plumbing rule over to the sewer and water side, or the other way around.

Renewal fees on this track are correspondingly lower: Sewer and Water Contractor $100.00, Sewer and Water Installer $25.00, Sewer and Water Apprentice over 3,400 hours $25.00, and Sewer and Water Apprentice under 3,400 hours $0.00.

That last line is worth pausing on. A first-stage sewer and water apprentice renews for nothing. North Dakota has removed the cost barrier to entry on this track entirely.

Water conditioning, and backflow

The third ladder is Water Conditioning, Contractor, Installer, Apprentice. Renewal fees are $40.00, $20.00, and $0.00 respectively, and both water conditioning exams are $0.00.

The fourth credential is Certified Backflow Assembly Tester, which the Board maintains as its own certified list.

Backflow is where the scope lines get sharp, and the Board answers it directly. Hooking up a backflow preventer to the main water supply requires a plumbing license. Testing the assembly is the separate certification.

What does not require a plumbing license in North Dakota

The Board publishes a short list of things people assume are licensed work and are not. This is useful in both directions, it tells you what you can staff without a license, and it tells you where a competitor undercutting you is operating legally rather than illegally.

• Rodding out drain lines, no plumbing license required.
• Hooking up irrigation sprinkler systems, no plumbing license required.
• Installing septic tanks and drain fields, no plumbing license required from the Plumbing Board, but you must be licensed through that district's Health Unit. The requirement moves, it does not disappear.

And what does require it:

• Hooking up backflow preventers to the main water supply, yes.
• Connecting to public water systems and sewers, yes, a plumbing license or a Sewer and Water Contractor license.

Plumbing Installation Certificates

North Dakota runs a reporting document most states do not. A Plumbing Installation Certificate is a form furnished by the Board to report plumbing work that is subject to inspection.

It is required for any plumbing installation that will require an inspection, and the Board is specific about who files it: the master or journeyman plumber, or the homeowner, if the homeowner is doing the installation, completes the certificate and returns it to the Board office along with the appropriate fees.

The Board also maintains its own inspectors and divides the state into inspection districts. If you are used to a purely municipal inspection regime, note that North Dakota's plumbing inspection authority runs through the state Board, not only through city hall.

Where the plumbing license sits relative to the contractor license

A North Dakota master plumber license lets you do plumbing work. It does not, by itself, let you contract.

Separately from the Plumbing Board, North Dakota requires a contractor license from the Secretary of State when the cost, value, or price of a job exceeds $4,000, that threshold and the licensing duty come from NDCC ch. 43-07, and it reaches subcontractors, general contractors, public contractors, and nonresident contractors alike. The Secretary of State's contractor license is graded by contract size into Class A through Class D, and it is an entirely different filing from anything the Plumbing Board issues.

So a plumbing company operating in North Dakota is typically carrying two credentials at once: a Secretary of State contractor license for the business, and a Plumbing Board master license held by a person inside that business. Neither substitutes for the other.

That two-track structure is the whole story of contractor licensing in North Dakota, and it has a direct bearing on who has to be on your payroll. We take it apart in detail in North Dakota's Two-Track System.

How North Dakota compares to its neighbors

If you are expanding across the northern tier, the differences are sharper than the map suggests.

Montana requires a business to name a single master plumber of record, in writing, a formal, filed attachment of one person to one company. North Dakota's Plumbing Board has no equivalent filing at the plumbing-license level; the attachment happens, if anywhere, on the Secretary of State's side.

Delaware has no journeyman plumbing license at all, a two-rung ladder where North Dakota has three. Maine repealed its plumbing company license outright in 2017 and now licenses only individuals.

The pattern across all four: the individual trade license is converging on a similar shape nationally, while the business authorization varies wildly from state to state. That is exactly the layer where multi-state contractors get caught.

For the electrical side of a North Dakota project, see How to Get an Electrician License in North Dakota. For mechanical work, note that North Dakota has no state HVAC license at all, the licensing is municipal, and we cover why in HVAC License North Dakota.

Frequently asked questions

How long does it take to become a master plumber in North Dakota?

Six years on the standard path, four years and 7,600 hours as a registered apprentice under a licensed master to qualify for the journeyman exam, then two years and 3,400 hours as a licensed journeyman to qualify for the master exam. You must also be at least twenty-one. Credit for a nine-month accredited plumbing program can offset part of the apprentice term, with the amount of credit scaled to grade average, but the calendar-year requirements are stated alongside the hour requirements and both have to be satisfied.

What does a North Dakota plumbing license cost?

The exams are $50.00 for both the master and journeyman plumber. Annual renewal is $200.00 for a master, $100.00 for a journeyman, and $20.00 to $75.00 for an apprentice depending on year. Late renewal adds $50.00. Sewer and water and water conditioning exams are $0.00. These are Board fees only and are subject to change, verify with the Board. Separately, a Secretary of State contractor license runs $100 to $450 for the initial filing depending on class, plus annual renewal of $30 to $90.

What does it cost to get a plumbing company licensed and operating in North Dakota?

That is a different question from the license fees, and the honest answer is that it varies. The board fees above are fixed and public. What is not fixed is everything around them: whether you already have a licensed master plumber inside the company or need to bring one in, which Secretary of State contractor class your contract sizes require, what your liability insurance costs given your loss history and scope, whether you have North Dakota-resident employees and therefore a Workforce Safety & Insurance obligation, whether you are also picking up city HVAC or electrical credentials, and how many states you are doing this in at once.

Those variables move the number more than the license fees do. If you want a real figure for your situation rather than a range that is wrong for everybody, that is what a scoping conversation is for, see Consultation Packages.

What score do I need to pass the North Dakota plumbing exam?

The administrative rule sets the passing grade at eighty percent for the master plumber examination and seventy percent for the journeyman plumber examination.

Can I use my plumbing license from another state in North Dakota?

Cross-state licensing questions are outside the scope of this guide. Contact the North Dakota State Plumbing Board directly regarding out-of-state credentials; requirements and documentation differ by license grade and by the state you are coming from.

Does North Dakota require continuing education for plumbers?

Yes. Journeyman and master plumbers must complete at least two to four credit hours within a two-year period. The Board publishes session schedules, a correspondence course, and approved online courses.

Do I need a plumbing license to install a septic system in North Dakota?

Not from the State Plumbing Board. You must be licensed through that district's Health Unit instead. The requirement moves to a different authority rather than disappearing.

Can a fourth-year apprentice work alone in North Dakota?

Yes. First, second, and third year apprentices must be under the direct supervision of a master or journeyman plumber. Fourth and fifth year apprentices may work by themselves. This is more permissive than most states and has real crew-scheduling value.

Who actually holds the license

Here is the structural point that matters if you are building a plumbing business in North Dakota rather than just working in one.

Every credential on this page is held by a person. The Plumbing Board licenses individuals, apprentices, journeymen, masters, installers, contractors, testers. A company cannot sit for the master exam. A company cannot accrue 7,600 hours. The competency lives in a human being.

The Secretary of State's contractor license, by contrast, is held by the business. And the business cannot legally perform plumbing work in North Dakota unless a properly licensed person is doing it.

That gap (business authorization on one side, personal trade competency on the other) is the gap a qualifying agent fills. In North Dakota, as everywhere, the person holding the trade license has to be genuinely inside the company: a real, full-time W-2 employee doing real work, not a name on a filing. Arrangements that treat a license as something to be rented out are a compliance problem in every state that has looked at them, and we have written about why in Is It Legal to Rent a Contractor License?.

If your North Dakota plumbing company needs a licensed master plumber on staff and you do not have one, that is the problem we solve. We place qualifying agents as full-time W-2 employees, see What Is a Qualifying Agent for how the role works, and Hire a Qualifying Agent if you need one placed in North Dakota.

And if you hold a North Dakota master plumber license and want to understand what that credential is worth to a company that needs it, see Become a Qualifying Agent.

Fees, hour requirements, cut scores, waiting periods, and continuing education rules on this page are set by the North Dakota State Plumbing Board and the North Dakota Secretary of State and are subject to change. Verify current requirements with the issuing authority before acting on them. The North Dakota State Plumbing Board is at 1110 College Drive Suite 210, Bismarck, ND 58501, 701-328-9977, ndplumb@nd.gov. Last reviewed September 2026.