Missouri · plumber licensing · verified July 2026
Missouri plumber license requirements
The short answer
As of July 2026, Missouri has no statewide plumber license; plumbing licensing is handled by city and county governments. RSMo Chapter 341 requires master and journeyman plumbers to obtain certificates in cities or towns of 15,000 or more inhabitants (341.010, through local boards of examiners) and authorizes first-classification counties to create plumbing boards (341.090-341.220). Where the statute applies, minimum qualifications are set by RSMo 341.170: journeyman applicants must be at least 21 with at least 5 years of experience as an apprentice under a master plumber, and master applicants at least 25 with 3 or more years as a licensed journeyman.
Do you need a license to work as a plumber in Missouri?
Missouri has no statewide license for plumbers. Cities and counties license the trade, so the requirement depends on where you work.
Major local licensing examples: Kansas City and St. Louis (city and county) operate their own plumber examination/licensing programs, and many other municipalities of 15,000+ population license journeyman and master plumbers through local boards per RSMo Chapter 341; plumbers must be licensed in each jurisdiction where they work. RSMo 341.170 also establishes separate journeyman/master drainlayer licenses, and licensed plumbers need a drainlayer license to perform drainlaying.
What licenses does Missouri issue?
No credential for this trade is issued at state level in Missouri; the classes below are issued by cities or counties, and the exact set depends on which one you work in.
Hours are what each class asks for on its own terms. Where a senior class shows fewer than a journeyman, the board is counting time served after the earlier license rather than from the start; the prerequisite column says which.
| License | On-the-job hours | Classroom hours | Exam |
|---|---|---|---|
| Journeyman Plumber (local license; statutory minimum qualifications) | not published | not published | Yes |
| Master Plumber (local license; statutory minimum qualifications) | not published | not published | Yes |
Source: the governing statute (revisor.mo.gov). Verified July 2026.
What exam does Missouri require?
Local journeyman/master plumber examinations. Administered by City/county boards of examiners (RSMo 341.020-341.050 for cities; 341.160 for county plumbing and sewer inspection boards).
How often do you renew, and what continuing education is required?
Renewal period: Set locally; RSMo 341.180 addresses fees and license terms for licenses issued under the county provisions
Continuing education: None required at state level; determined by local jurisdictions.
How does the apprenticeship route work?
Apprenticeship is served under the direction and supervision of a master plumber; RSMo 341.170 makes 5 years of such apprenticeship the minimum qualification for a journeyman license in jurisdictions covered by the chapter. Registered apprenticeship programs (union JATC and open-shop) are commonly used to satisfy local boards' experience requirements.
Which states does Missouri have license reciprocity with?
Missouri does not license this trade at state level, so there is no state agreement to publish. Whether an out-of-state license helps is decided by the city, county or contractor board that issues the credential where you intend to work.
How does Missouri compare to neighboring states?
Requirements stop at the state line, which matters if you live near one or expect to move. Here is what the neighboring states ask of the same trade.
| State | Journeyman hours | Licensing model |
|---|---|---|
| Missouri | not published | City or county |
| Arkansas | not published | Statewide |
| Illinois | not published | Statewide |
| Iowa | not published | Statewide |
| Kansas | not published | City or county |
| Kentucky | not published | Statewide |
| Nebraska | not published | City or county |
| Oklahoma | not published | Statewide |
| Tennessee | not published | Contractor level only |
Source: state licensing boards. Verified July 2026.
Sources and verification
Every fact on this page traces to one of these
- RSMo 341.170 - Qualifications for licenses (journeyman, master, drainlayer)
- RSMo 341.010 - Plumbers must have certificates (cities of 15,000 or more)
- RSMo Chapter 341 - Plumbers and Plumbing (chapter index)
Last verified July 2026. Found an error? Report it and it will be corrected and logged on the corrections page.
Other states with published requirements for this trade: Montana, New Hampshire, New Jersey.
Price the whole path with the license cost estimator, or weigh earning against paying for school with the apprenticeship comparison. Back to plumbers overview.
Licensing requirements change between our verification sweeps. This page is informational only, so confirm current requirements with your city or county building department before making decisions. Not legal advice.