How to Become a Plumber in Missouri


In Missouri, unlike in the other states such as Iowa or Mississippi, there is no licensing body for plumbers and contractors. Instead, aspiring plumbers need to go through a licensure process at their local or county level governance based on city planning directives.

Thus, despite without a proper licensing body, you still need a license to become a professional plumber in Missouri.

Plumbing is a professional skill. You need a combination of education and experience to make a career in plumbing.

Read on to find out how to obtain a journeyman and/or a master’s license in plumbing to practice in the major cities of Kansas City and St. Louis in the state of Missouri.

Types of Plumbing Licenses in Missouri

There are two types of plumbing licenses in Missouri

  • Journeyman License: With this license, you can independently work on your own plumbing projects as well as hire apprentices to work under your supervision.
  • Master License: With this license, you can be responsible for planning and handling bigger projects as well as hiring apprentices to work under your supervision. It is the highest level of expertise in plumbing.

General Qualifications to Become a Plumber in Missouri

  • Be at least 21 years of age
  • Furnish certificate for application of plumbing license
  • Pay application and license fees
  • Submit two letters of recommendation duly attested by the notary from past employers under who you may have apprenticed
  • Have a minimum of two years of plumbing experience
  • Passed the relevant exam with 70% or higher

Requirements for Plumbing Apprenticeship in Missouri

Though Missouri does not mandate apprenticeship to eventually become a master plumber, an apprenticeship provides that initial exposure required to fulfill the experience criteria of a journeyman application.

This initial work experience can be gained by enrolling in a plumbing vocational program at a community college, or by working under the supervision of an experienced master or journeyman plumber who will eventually write your letter of recommendation.

You can get an apprentice job by registering at the Missouri Government Job Portal. By registering here, you will benefit from jobs that provide you with hands-on practical knowledge of plumbing, reward you with new skills, and give national recognition for your learning.

Journeyman Plumbing Gas Examination

You need to take a gas examination by registering at the Prometric. If you want to practice professionally in Kansas City, you need to pass this exam with 70% or higher. The score certifies you as a bonafide journeyman plumber.

Plumbing Journeyman Exam

This exam tests your knowledge in the installation, repair, maintenance, and anything related to plumbing like piping, waste, sanitation, water supply, fixtures, and so on.

Journeyman plumbing gas examination is an open book exam, and topics covered in this exam are

  • General Knowledge
  • General Regulations
  • Plumbing Fixtures
  • Water Supply Systems
  • Drainage, Waste, and Sanitary Vents
  • Indirect Waste
  • Roof Drain Piping
  • Specialty Piping
  • Isometric Analysis
  • Fuel Gas

You need to visit the Prometric website to schedule your exam.

Requirements for Master’s Plumber License in Missouri

This is the highest level of plumbing expertise. To obtain a master’s license, you need to

  • Apply for a contractor’s license by paying an application fee of $60.
  • Check any of the below classifications for your license categories
  • Demolition Contractor Class I
  • Demolition Contractor Class II
  • Electrical Contractor Class I
  • Electrical Contractor Class II
  • Electrical Contractor Class III
  • Elevator Contractor Class I
  • Elevator Contractor Class II
  • Elevator Contractor Class III
  • Fire Protection Contractor Class I
  • Fire Protection Contractor Class II
  • Fire Protection Contractor Class III
  • Gas-fired Appliance Contractor
  • Mechanical Contractor
  • Pipe fitting Contractor
  • Residential Building Contractor
  • Plumbing Contractor
  • Sign Contractor
  • Have at least one year of experience as a licensed journeyman
  • Submit two notarized letters of recommendations from previous co-workers or employers
  • Score 70% or higher in the master plumbing with gas exam administered by Prometric

Topics Covered by the Master Plumbing Gas Exam

This is the same open book exam as the journeyman plumbing gas exam. It covers similar topics but requires an advanced level of knowledge in the following topics

  • General Knowledge
  • General Regulations
  • Plumbing Fixtures
  • Water Supply Systems
  • Drainage, Waste, and Sanitary Vents
  • Indirect Waste
  • Roof Drain Piping
  • Specialty Piping
  • Isometric Analysis
  • Fuel Gas

Good Plumbing Programs in Missouri

To gain training and knowledge through apprenticeship, these are the popular trade schools to choose from

  • Pipefitters Training Centre, Kansas City
  • Plumbers Local 8, Kansas City
  • Vatterott College, Kansas City
  • UA Local 562 Plumbers Pipefitters & Plumbers Training Centre, St. Louis
  • Ranken Technical College, St. Louis
  • Vatterott College, Sunset Hills
  • Vatterott College, St. Ann
  • Vatterott College, Springfield
  • Linn State Technical College, Linn

Professional License Search

You can check the status of your license (validity, renewal, etc.) on these professional search engines

License Reciprocity

A reciprocity agreement between states means that the plumbing license issued by one state is recognized by another. For example, a plumbing license issued by Alabama is recognized by Missouri. This means that an aspiring plumber with a license from Alabama will have their exam requirement waived if they want to practice plumbing in Missouri.

But, so far Missouri does not have any data for license reciprocity with other states. One has to check by calling the city hall if they are eligible for an exam waiver because of a recognized, pre-existing plumbing license.

Further, you will need to produce a copy of all your active licenses as well as provide notarized letters of recommendation from your past co-workers and/or employers.

Obtaining the Plumbing License in Missouri

Once you’re through with your exam, you need to submit your scores to the board of certification. Though Missouri does not have a formal board issuing certificates, you need to submit your result to the county level within ninety days of taking your exam.

Any delay would mean you need to retake the exam by paying the application fee again.

By implication, this ninety-day rule also means that if you fail your exam, you won’t be to retake your exam before ninety days.

Salary Expectations of a Plumber in Missouri

Like in any other profession, salaries vary depending on the expertise level, experience level, certifications, city of residence and practice, and so on.

In Missouri, the average salary of a plumber is $56,000 which is relatively higher than in other states like Iowa and Mississippi. The range usually falls between $49,000 and $64,000 with St. Louis and Kansas City being the two highest paying states.

Career Outlook of a Plumber in Missouri

Job prospects are on a rise for plumbers in Missouri. It is projected that plumbing jobs will rise by 16% in the next ten years. As the global capital markets will only increase over time requiring more spaces for offices and residences, so will the need for more plumbers.

In terms of job satisfaction, it is substantially higher for a plumber than any other professional. While it is true that beyond the master’s level there may be an element of stagnation, that comes with the silver lining of more time for home.

Hence, a plumbing job may be a good option for those looking for a good home and work balance.

Joining a Workers’ Union

Before you decide to join a workers’ union, you need to remember that any union works for collective benefits and not for individual benefits. You may not agree with certain decisions the union collectively takes. But as a member of that union, you need to honor any decision it takes regardless of your personal opinion on them.

By joining a workers’ union, you can have the following benefits:


Who Issues Plumbing Licenses in Missouri?

Cities or counties issue licenses to plumbers in the absence of a certified body.

Can I Work in Any Other State With a Missouri Plumbing License?

The answer can be both yes and no depending on individual cases. You have to call the city hall, produce all active licenses, and they will decide on a case-by-case basis whether your existing licenses are eligible for reciprocity.

How Much Does a Plumbing License Cost in Missouri?

This fee varies from city to city. For example, the City of Jefferson has a paltry $12 application fee for an apprenticeship license, $105 for a journeyman and master plumbing license, and $210 for a contractor’s license.

Are the Journeyman and Master License Exams Open Book?

Yes, but you’re only allowed to take pre-authorized books.

What’s the Minimum That I Have to Score in the Journeyman and Master’s Plumbing Exam?

You have to score a minimum of 70%.

In Conclusion

Every state has its own body certifying plumbers. Some states have formal bodies while others don’t. Missouri does not have a certifying board. Instead, local city or county level authorities decide on the licensure. This is also true on the issue of license reciprocity in Missouri which is decided on a case-by-case basis.

Before embarking on a career in plumbing, contemplate the choice of your city/state of practice. Locations also have implications for your salary.

Overall, plumbing jobs are lucrative to some as they offer a stress-free work life ensuring more undivided time at home.

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