Plumbing License in Missouri: Requirements & How to Get One

No, Missouri doesn’t have a statewide plumber license. A plumbing license in Missouri comes from the city or county where you work. State law in RSMo Chapter 341 pushes licensing down to cities of 15,000 or more people and to first class counties that opt in. Kansas City, St. Louis City, St. Louis County, Springfield, and Columbia each run their own program, with their own tiers, exams, and fees.

Who licenses plumbers in Missouri

There’s no state plumbing board. Here’s what the law says.

• Cities of 15,000 or more. RSMo 341.010 says master and journeyman plumbers working in these cities must hold a certificate. Each city runs its own board, code, and permits.
• First class counties. RSMo 341.100 lets a first class county adopt a county plumbing law, but only after the county commission makes a public health finding. The county board then licenses master plumbers, journeyman plumbers, and drainlayers (341.160).
• Cities inside those counties. Under RSMo 341.210, the county law doesn’t apply inside a city that regulates plumbing by its own ordinance.
• Charter cities. The revisor’s annotation to RSMo 341.040 notes a 1977 Missouri Supreme Court case holding Chapter 341 doesn’t apply to constitutional charter cities. Kansas City, St. Louis, Springfield, and Columbia all run their own programs under their own codes.

We checked for a statewide fix. Bills to make local plumber licenses honor each other (HB 1926 in 2024, HB 2394 in 2026) were filed, but Chapter 341 on the revisor’s site shows no new section as of October 2026. Missouri does have an optional statewide electrical contractor license (RSMo 324.900 and up), but nothing like it for plumbers. The one state plumbing related credential we found is the Department of Natural Resources certified backflow prevention assembly tester, which is not a plumbing license.

Requirements change, so confirm with your local board before you apply. This page is a plain-English guide, not legal advice.

License types

Every city names its tiers differently. Here’s what the big programs publish.

• St. Louis City. Registered Plumber Apprentice, Experienced Plumber Apprentice, Journeyman Plumber, Master Plumber, and Master Drainlayer, set by Ordinance 71644 (the city’s 2021 Uniform Plumbing Code).
• Kansas City. Journeyman Plumber and Master Plumber Certificates of Qualification, plus a separate contractor license for the business, per KC BizCare.
• Springfield. Apprentice, Journeyman Plumbing, and Master Plumbing trade certifications, plus Journeyman and Master Gas as separate tracks.
• Columbia. Master (Type A), Journeyman (Type B), Residential Journeyman (one and two family homes only), Maintenance Journeyman, and Apprentice.
• St. Louis County. Licenses journeyman and master plumbers through its Department of Transportation and Public Works. The county’s pages blocked our tools, so check its plumbing licensing page directly.

How to become a plumber in Missouri

Honestly, there’s no single state path. You pick the city or county where you’ll work most and follow its ladder.

1. Get hired and registered as an apprentice. In St. Louis City, the master who hires you has to register you before you start, and you must enroll in a DOL registered apprenticeship or a board approved school within six months.
2. Put in the years. St. Louis City wants at least 5 years as an apprentice under a master or journeyman for the journeyman license. Columbia wants 8,000 on the job hours under a journeyman. Springfield wants 4 years under a plumbing master, or 6 years of plumbing experience.
3. Pass the journeyman exam. Most boards approve your experience first, then send you to a national testing company.
4. Step up to master. St. Louis City requires 5 years as a licensed journeyman. Springfield requires 4 years as a certified journeyman, or 10 years of plumbing experience. Columbia requires 4,000 hours as a journeyman under a master. Kansas City’s reference form asks for 3 years of full time experience, with at least 2 years at journeyman level.
5. Add the business side. Masters who pull permits usually need a bond, insurance, and a city business license on top of the certificate.

Exams

• Kansas City. Results must come from a recognized testing agency such as Prometric or ICC. The city may accept a comparable exam you already passed.
• Springfield. ICC exams through Pearson VUE. You need 75% or better. Board approval to test is good for one year.
• Columbia. The standard master or journeyman exam from Prometric or the ICC National Standardized Examinations program. You can retest after 30 days.
• St. Louis City. A written exam designed or picked by the Board of Examiners. If you fail, you can retake it after 90 days, and every 90 days after that.

Renewal

• St. Louis City. All master, drainlayer, and journeyman licenses renew on one date, December 31, 2023, and every 3 years after. CE is 12 PEU (Professional Education Units) per three year cycle for both masters and journeymen.
• Kansas City. A certificate renews every four years. If you let it lapse for two years, it goes inactive and you retest.
• Springfield. The city’s fee schedule lists annual renewal fees for masters, journeymen, and apprentices.
• Columbia. Certificates renew every 3 years, due by January 1 of the renewal year. No retest is needed to renew.

Kansas City, Springfield, and Columbia don’t publish a plumber CE requirement on the pages we read. Ask the city before your renewal date.

Cost

These fees come from each city’s official ordinance or fee sheet:

• St. Louis City: $50 application (all classes), $50 per exam, $50 journeyman license (3 years), $300 master plumber (3 years), $300 master drainlayer, $600 combined master plumber and drainlayer, $25 apprentice registration (5 years). Late renewal adds a $100 processing fee. Masters also need a $25,000 surety bond and $1,000,000 liability insurance.
• Kansas City: $60 nonrefundable application fee, exam fee paid to the testing agency, then $181 every four years to renew.
• Springfield: about $125 for the ICC exam, $25 journeyman or $50 master card, $10 apprentice registration. Annual renewal is $25 journeyman, $50 master, $10 apprentice.
• Columbia: $50 application fee (refunded if you show up for your interview), $30 journeyman or $90 master certificate, same amounts to renew every 3 years. Contracting masters file a $10,000 bond.

Springfield’s posted fee sheet is dated 2024, so confirm current numbers when you apply.

Reciprocity

Reciprocity in Missouri is local. There’s no state agreement with any other state, because there’s no state license. What’s published:

• Columbia. Honors licenses from other jurisdictions if you meet Columbia’s experience minimums and passed a Prometric or ICC exam for that license type.
• Springfield. Accepts a score of 75% or better from Prometric, Experior, Block, or ICC if it’s the same exam Springfield requires, plus your experience forms.
• Kansas City. May accept a comparable passing score from a standard national exam. We found no official plumbing reciprocity deal across the KC metro.

Coming from Kansas or Illinois? Expect to apply city by city. See our plumbing license reciprocity guide for how other states handle it.

How to apply

• Kansas City. Get a KC business license, apply for your Certificate of Qualification in CompassKC, then apply for the contractor license.
• St. Louis City. Applications go to the Plumbers and Drainlayers Board of Examiners, which meets the fourth Monday of each month. Call (314) 622-3313.
• Springfield. Submit the trade certification packet with one notarized experience form per employer. The board meets the first Thursday of each month.
• Columbia. Use the city’s plumbing certification application, showing your hours by employer.

One more thing. Columbia’s Board of Plumbing Examiners page now says the board is no longer active, though it still posts the plumbing code text. Call the city to confirm who reviews applications.

FAQ

Does Missouri have a state plumbing license?

No. Licensing is local under RSMo Chapter 341 and city charters. A 2026 bill to make local licenses reciprocal did not become law.

Can I work anywhere in Missouri with a Kansas City or St. Louis license?

Not automatically. Each city can require its own certificate, so check first.

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

In the cities we checked, 8 to 10 years. St. Louis City is 5 years as an apprentice plus 5 as a journeyman. Springfield is 4 plus 4.

Do I need a license in a small town?

Maybe. State law targets cities of 15,000 or more, but smaller towns can still pass their own rules. Ask city hall.

Next steps

Pick the city where you’ll do most of your work, call its board, and ask for the current application and fee sheet. To compare Missouri with other states, see our plumbing license by state page, the full plumbing license guide, and plumbing license cost by state. Working the state line? Check the Kansas plumbing license and Illinois plumbing license pages too. Once you’re a master and ready to run your own shop, read how to start a plumbing business.