State plumbing guide · MO
Plumbing in Missouri
Missouri leaves plumbing licensing and code adoption to cities and counties, so Kansas City, St. Louis and smaller towns each set their own rules. Ask your local building department which code and license apply.
- Median home built
- 1978
- Built before 1980
- 52%
- Owner-occupied
- 69%
- Winter
- Regular hard freezes
- General statewide rating
- Plumbing code
- State code
- City guides
- 2
Housing figures: U.S. Census Bureau, ACS 2024 1-year (B25035, B25034).
Missouri city plumbing guides
How to check a plumber's license in Missouri
Plumbing is licensed locally in Missouri. In Kansas City, plumbing work requires a city Certificate of Qualification (journeyman or master plumber) and a contractor license issued through the City Planning and Development Department. [1]
Missouri's older housing stock
Statewide, the median home was built in 1978 and 52% of homes predate 1980. Homes like that were usually built with copper supply, early plastic (ABS or PVC) drains, some cast iron. The city guides below show how much that varies within the state.
Which plumbing code applies in Missouri
St. Louis County licenses master and journeyman plumbers and administers its own plumbing code through its Department of Transportation and Public Works, which publishes lists of licensed master plumbers. [2]
Seasonal problems to plan for in Missouri
- Winter
- Hard freezes: protect exposed pipes, disconnect hoses. Frozen pipes.
- Storm season
- Heavy rain: sewer backups and sump pump failures.
Missouri plumbing questions
How do I check a plumber's license in Missouri?
Ask which city or county license the plumber holds, and verify it with that local licensing office.
Which plumbing code applies in Missouri?
It depends on the city or county. Kansas City, St. Louis and other jurisdictions adopt their own plumbing codes.
Sources (3)
- U.S. Census Bureau, ACS 2024 1-year (B25035, B25034) · checked 2026-10-01
- City of Kansas City, Missouri, Contractor Licensing · checked 2026-10-01
- St. Louis County, Plumbing Licensing · checked 2026-10-01