How to Become a Licensed Plumber in Missouri

Dreaming of a stable, hands-on career with strong earning potential? How to become a licensed plumber in Missouri is a common question for skilled trade newcomers—and for good reason. With growing infrastructure needs and a nationwide shortage of qualified tradespeople, Missouri offers excellent opportunities for those ready to enter the plumbing field. In this guide, we’ll walk you through every requirement, timeline, and insider tip you need to get licensed and start working legally in the Show-Me State.

What Are the Basic Requirements to Become a Plumber in Missouri?

Missouri does not issue state-level plumbing licenses. Instead, licensing is handled at the city or county level, with St. Louis and Kansas City being the two major jurisdictions that require formal licensure. This decentralized system means your path depends on where you plan to work—but the core steps remain similar.

General Eligibility (Across Most Missouri Jurisdictions):

• Be at least 18 years old
• Hold a high school diploma or GED
• Complete a plumbing apprenticeship (typically 4–5 years)
• Pass a local licensing exam
• Provide proof of work experience under a licensed plumber

💡 Pro Tip: Even in areas without mandatory licensing (like Springfield or Columbia), many employers and clients prefer or require certification. Getting licensed boosts your credibility and income potential.

Step-by-Step Guide: How to Get Licensed

Step 1: Complete High School or GED

You’ll need foundational math, reading, and problem-solving skills. Courses in algebra, physics, or shop class are especially helpful.

Step 2: Enroll in a Plumbing Apprenticeship

Most Missouri plumbers train through a registered apprenticeship program, which combines:

• 8,000+ hours of on-the-job training (typically 4–5 years)
• 500+ hours of classroom instruction

You can find programs through:

• Local unions (e.g., UA Local 540 in St. Louis)
• Trade schools (e.g., Ranken Technical College, State Technical College of Missouri)
• Contractors who sponsor apprentices

⏱️ Timeline Note: Apprentices usually earn $15–$20/hour in Year 1, with wages increasing by 5–10% each year as skills improve.

Step 3: Gain Work Experience Under a Licensed Plumber

Missouri jurisdictions require documented experience. For example:

• St. Louis: 4 years (8,000 hours) under a Master Plumber
• Kansas City: 4 years of full-time plumbing work

Keep detailed logs—many cities require signed affidavits from your supervising plumber.

Step 4: Apply for the Journeyman Plumber Exam

Once you meet experience requirements, apply through your local building department:

You’ll need to submit:

• Proof of experience
• ID and residency documents
• Completed application form

Step 5: Pass the Licensing Exam

Exams test knowledge of:

• Missouri plumbing codes (based on the International Plumbing Code)
• Pipe sizing, drainage, venting
• Safety and backflow prevention
• Local amendments

📚 Study Resources:

• International Plumbing Code (IPC)
• PSI Exams practice tests
• Local building department study guides

Passing score is typically 70–75%. You can retake the exam if needed (fees may apply).

Step 6: Receive Your License & Start Working

Once licensed, you can legally perform plumbing work independently in that jurisdiction. Some cities issue physical cards; others provide digital certificates.

Do You Need a State License in Missouri?

No. Missouri is one of the few states that does not regulate plumbing at the state level. According to the Missouri Division of Professional Registration , plumbing licensure is entirely local. This means:

✅ You can work in unincorporated areas without a license
⚠️ But cities like St. Louis and KC require it by law
✅ Always check with your local building department before starting work

🔍 Expert Insight:
“Many new plumbers assume Missouri is ‘license-free’ and skip certification,” says Mark Reynolds, a Master Plumber in St. Louis with 22 years of experience. “But without a local license, you can’t pull permits—and that limits your job scope and client trust.”

Missouri Plumbing Career Outlook & Earnings

The U.S. Bureau of Labor Statistics (BLS) projects 5% job growth for plumbers nationwide from 2022–2032—faster than average. In Missouri, demand is even stronger due to aging infrastructure and new residential construction.

Average Salaries in Missouri (2024 Data):

Self-employed plumbers in Kansas City or St. Louis often earn $80,000+ with strong client bases.

Advancing to Master Plumber in Missouri

After working as a Journeyman for 2–4 years (depending on city), you can apply for Master Plumber status. This allows you to:

• Pull permits independently
• Start your own plumbing business
• Supervise apprentices

Requirements typically include:

• Additional work hours (e.g., 2 more years in St. Louis)
• Passing a more advanced exam
• Business license (if self-employed)

Common Mistakes to Avoid

🚫 Assuming no license is needed statewide → Always verify local rules
🚫 Skipping code updates → Plumbing codes change every 3 years
🚫 Not keeping work logs → You’ll need them for your application
🚫 Ignoring insurance → General liability insurance is often required for contractors

Frequently Asked Questions (FAQ)

Q1: How long does it take to become a licensed plumber in Missouri?

A: Typically 4–5 years, including apprenticeship and exam prep. If you already have experience, you may qualify faster in some cities.

Q2: Can I get a plumbing license in Missouri with an out-of-state license?

A: Missouri doesn’t have state reciprocity, but some cities (like Kansas City) may waive parts of the exam if you’re licensed in a comparable jurisdiction. Check with the local building department.

Q3: Is formal schooling required, or can I learn on the job?

A: While on-the-job training is essential, most jurisdictions require classroom instruction as part of your apprenticeship. Trade schools like Ranken Tech help fulfill this requirement.

Q4: Do I need a license to do small plumbing jobs in Missouri?

A: In unincorporated areas, maybe not—but in St. Louis, Kansas City, and other cities, any plumbing work requiring a permit must be done by a licensed plumber. DIY or unlicensed work can lead to fines or voided insurance claims.

Q5: How much does it cost to get licensed?

A: Total costs range from $300 to $600, including application fees, exam fees, study materials, and background checks (if required).

Q6: Where can I find approved apprenticeship programs?

A: Visit the U.S. Department of Labor’s Apprenticeship Finder or contact local unions and technical colleges. Ranken Technical College (St. Louis) and State Tech (Linn) offer highly regarded programs.

Conclusion

Becoming a licensed plumber in Missouri is a smart, future-proof career move—with strong demand, good pay, and clear pathways to advancement. While the process varies by city, the core steps are consistent: train, gain experience, pass the exam, and get licensed locally.

Whether you’re a recent high school grad or switching careers at 40, plumbing offers job security, independence, and the satisfaction of solving real problems every day.

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All information is accurate as of 2025. Licensing rules can change—always verify with your local building department before applying.

🔗 Authoritative Reference: Plumbing – Wikipedia (for historical and technical context on plumbing systems and standards)