How plumber licensing works in Missouri

Journeyman level Licensed by cities or counties, not the state What's a journeyman?

The license pathway in Missouri

1. 1

   Apprentice (local rules)

   No state license. You work for a licensed plumbing contractor; in the City of St. Louis, the plumbing board reviews apprentice applications. Union apprenticeships run five years. [1][6][15]

2. 2

   Journeyman Plumber (Kansas City)

   • 2 years of experience
   • Yes: journeyman plumbing with gas (Prometric 30615) or journeyman plumber with gas (ICC 675)
   • $60 application

   Lets you work at the trade of plumbing as an employee of a licensed plumbing contractor in Kansas City. You need 2 years of plumbing installation experience shown by two notarized reference letters, a diploma or GED, and you must be 21. [4]

3. 3

   Master Plumber (Kansas City)

   • 3 years of experience
   • Yes: master plumbing with gas (Prometric 30315) or approved substitute
   • $60 application

   Qualifies a licensed plumbing contractor in Kansas City; all its work is done by or under the master plumber. Needs 3 years full-time at the trade, including 1 year as a certified journeyman, and age 21. [10]

Who licenses plumbers in Missouri

Missouri's Division of Professional Registration, which runs most state licensing boards, has a statewide license for electrical contractors but no board for plumbers. Plumbing licenses come from cities and counties.

An old state law (RSMo 341.010 to 341.080, carried in Missouri's statutes since at least the 1909 revision) says anyone working as a master or journeyman plumber in a city of 15,000 or more must first get a certificate, by passing an exam given by a city board of examiners of plumbers. The Revisor's notes to the law cite a 1977 Missouri case (State ex rel. Sprague v. City of St. Joseph) holding that this chapter doesn't apply to a constitutional charter city. A separate state law (RSMo 341.090 to 341.220) takes effect in a first-class county only if its county commission adopts it; there, journeyman plumbers must be 21 with 5 years as an apprentice under a licensed master plumber, and master plumbers must be 25 with 3 years as a licensed journeyman. [1][2][3][7][8][9]

Kansas City

Kansas City's City Planning and Development Department licenses plumbers. A journeyman plumber certificate lets you work at the trade as an employee of a licensed plumbing contractor. You need two notarized reference letters from companies in the plumbing trade showing at least 2 years of plumbing installation experience, a diploma or GED (or an extra year of experience per missing year of high school), age 21, a $60 application fee, and a passing score on Prometric's journeyman plumbing with gas exam (30615) or ICC's journeyman plumber with gas exam (675). You must pass and have the score reported within one year of your application being processed.

A master plumber certificate requires 3 years full-time in plumbing, including 1 year as a certified journeyman (Kansas City or an equivalent jurisdiction), age 21, a diploma or GED, and Prometric's master plumbing with gas exam (30315). The licensed plumbing contractor's work must be done by or under a master plumber. Apply through the city's contractor licensing page. [4][10][11]

St. Louis County and the City of St. Louis

St. Louis County gives journeyman and master plumber exams through IAPMO. You need Plumbing Board approval before you register. The journeyman exam is open book: a 75-question written exam (3 hours), an isometric drawing (1.5 hours) and three practical exams (3 hours), and you must score 75% on every part. It is based on the St. Louis County Plumbing Code and the 2015 Uniform Plumbing Code. IAPMO's journeyman fees are $175 online written, $235 in-person written and $190 practical and isometric; on Jan. 1, 2027 the in-person written fee rises to $250 and the practical and isometric fee to $225. As of October 2026, the next in-person exam date at the Local 562 training facility in Earth City is Jan. 9, 2027 (registration closes Dec. 22, 2026).

In the City of St. Louis, plumbing permits go only to plumbing contractors licensed by the city's Building Division. The Plumbers and Drainlayers Board of Examiners hears complaints against master plumbers, drainlayers and licensed journeyman plumbers and reviews apprentice applications. Call the Building Division at (314) 622-3313. [5][6][12][13][14]

Union and open-shop apprenticeships

The union plumbing apprenticeships listed here (Plumbers Local 8 and UA Local 562) are United Association programs that run five years. At Plumbers Local 8 in Kansas City, each year includes 1,700 to 2,000 hours of on-the-job training and at least 216 classroom hours; you must be 18 and have a diploma or GED. UA Local 562 (plumbers and pipefitters, St. Louis area) requires a diploma or equivalent, a math exam, a drug test, a physical and a driver's license; apprentices can also earn an associate's degree in apprenticeship pipefitting.

ABC Heart of America runs an open-shop plumbing apprenticeship from Kansas City and Fenton; you apply with copies of your diploma, GED or transcript and driver's license at age 18. See also our guide to helper jobs. [15][16][17]

If you're licensed in another state

Missouri's universal license recognition law (RSMo 324.009) does not apply to the occupations listed in RSMo 290.257(6), which include plumbers and pipefitters, and it doesn't apply to licenses issued by cities or counties.

Kansas City accepts current certification in the same classification from another jurisdiction with equal or higher standards in place of reference letters, and may waive its own exam for a comparable Prometric or ICC exam you've passed. Its master plumber route counts journeyman certification from any jurisdiction with equivalent or higher standards. Confirm with the city before you apply. [4][10][18][19]

Steps to get licensed in Missouri

1. Get hired or join an apprenticeship

   Apply to a registered program such as Plumbers Local 8, UA Local 562 or ABC Heart of America, or get hired by a licensed plumbing contractor. [15][16][17]

2. Learn your city's or county's rules

   Missouri has no state plumbing license, so ask the city or county where you'll work. In the City of St. Louis, the Plumbers and Drainlayers Board of Examiners handles apprentice applications and licenses. [1][6]

3. Get your journeyman certificate

   In Kansas City, after 2 years of plumbing experience and at age 21, apply through CompassKC with two notarized reference letters and the $60 fee, then pass the Prometric or ICC journeyman plumbing with gas exam within a year. [4][11]

4. Move up to master plumber

   Kansas City requires 3 years full-time in the trade, including 1 as a certified journeyman, and the Prometric master plumbing with gas exam. The master certificate holder qualifies the plumbing contractor's license. [10]

Where to get the hours

Programs that train plumbers in or for Missouri, from their own official pages. Listed by type, not ranked.

• Union

  Plumbers Local 8 apprenticeship (Kansas City)

  United Association five-year plumbing apprenticeship; apply at 5950 Manchester Trafficway or download the application. [15]

• Union

  UA Local 562 apprentice program (St. Louis area)

  Five-year plumbers and pipefitters apprenticeship. As of October 2026 applications are closed while new periods are set; an interest form is open. [16]

• Open shop

  ABC Heart of America plumbing apprenticeship

  Open-shop plumbing apprenticeship from training facilities in Kansas City and Fenton. [17]

• State program

  Apprenticeship Missouri

  Lists of U.S. Department of Labor-registered programs in Missouri by occupation, location and sponsor. [20]

• Other

  U.S. Department of Labor Apprenticeship Finder

  Search registered plumbing apprenticeships by location. [21]

Licensed in another state?

Questions people ask