Plumber License Requirements

Install and repair water supply lines, drainage, and fixtures. Compare requirements across all 50 states.

States Require License

$328

Average Initial Cost

States Require Exam

About Plumber Licensing

Plumbers install, repair, and maintain piping systems that carry water, gas, and waste in residential, commercial, and industrial buildings. Their work ensures clean water delivery, proper drainage, and safe gas distribution — all of which are critical to public health and safety.

Modern plumbing involves far more than pipe fitting. Plumbers must understand water pressure dynamics, drainage calculations, venting requirements, and backflow prevention. They work with a variety of materials including copper, PVC, PEX, cast iron, and stainless steel, and must be proficient with soldering, brazing, and mechanical joining techniques.

Licensing Landscape

Plumbing is one of the most consistently licensed trades across all 50 states due to its direct impact on public health. Most states use a tiered licensing system with apprentice, journeyman, and master plumber levels. Journeyman licensure typically requires 4-5 years of apprenticeship and passing an exam based on the Uniform Plumbing Code (UPC) or International Plumbing Code (IPC), depending on the state. Master plumber status requires additional experience and a separate or more comprehensive exam.

Common Requirements

8,000-10,000 hours of apprenticeship (4-5 years)
Pass journeyman or master plumber exam
Knowledge of UPC or IPC (varies by state)
Backflow prevention certification in many states
Liability insurance required in most states
Continuing education for renewal

What Does a Plumber Do?

Install water supply lines, drainage systems, and fixtures

Read plumbing blueprints and calculate pipe sizing

Solder, braze, and join various pipe materials

Install and repair water heaters and boilers

Test systems for leaks using pressure gauges

Install backflow prevention devices

Repair and replace sewer lines and drain systems

Ensure compliance with local plumbing codes

Career Outlook

Average Salary Range

$55,000 - $95,000

Projected Growth

2% (2022-2032)

Plumbers enjoy strong and stable demand driven by new construction, the aging housing stock requiring repairs and upgrades, and increased focus on water conservation and efficiency. Green plumbing technologies, water reclamation systems, and medical gas installation offer growing specialty niches. The trade consistently ranks among the highest-paid skilled trades.

Frequently Asked Questions

Do plumbers need a separate license for gas work?

In many states, yes. Gas fitting or gas piping work often requires a separate endorsement or license in addition to your plumbing license. Some states include gas work under the master plumber license but not the journeyman level.

What plumbing code does my state use?

States either follow the Uniform Plumbing Code (UPC) or the International Plumbing Code (IPC). Western states generally use the UPC, while most eastern and central states use the IPC. Your licensing exam will be based on whichever code your state has adopted.

How long is the plumbing apprenticeship?

Most states require between 8,000 and 10,000 hours of supervised work experience, which translates to roughly 4-5 years of full-time apprenticeship. During this time, apprentices also complete related classroom instruction.

Find Your State's Plumber Requirements

Select your state below to see the specific licensing requirements, fees, exams, and step-by-step application process for plumbers.

Plumber License by State

Alabama