- Master: hold a journey license for at least two years and complete 3,750 hours of training under a licensed master plumber. Journey: hold an apprentice license for at least four years, complete 7,500 hours under a master and 32 hours of backflow prevention testing training.
- Plan for a trade exam.
- Every two years from the date of issue. Maryland plumbing licenses have no continuing education requirement. A license lapsed more than four years means a new application and exam.
Do you need a state license in Maryland?
Maryland licenses plumbing work at the state level through the Maryland State Board of Plumbing, Maryland Department of Labor. Below is what the board asks for, in the order you will run into it.
Baltimore County and the Washington Suburban Sanitary Commission (Prince George's and Montgomery Counties) issue their own plumbing licenses and have their own plumbing code.
Maryland license types for plumbing work
Maryland splits the work into 4 licenses. Pick the one that matches the jobs you take, since working outside its scope is the same as working without one.
| License | What it covers |
|---|---|
| Master Plumber/Gas Fitter | Top plumbing and gas license |
| Journey Plumber/Gas Fitter | Plumbing and gas work after an apprenticeship |
| Apprentice Plumber/Gas Fitter | Learner license, minimum age 16 |
| Master Natural Gas Fitter | Natural gas work for non-plumbers |
Steps to get licensed in Maryland
- Get an apprentice plumber/gas fitter license (age 16 or older) and work under a licensed master.
- After four years and 7,500 hours plus 32 hours of backflow training, pass the PSI journey exam.
- Hold the journey license two years and log 3,750 more hours under a master.
- Apply through PSI with proof of hours and backflow certification, and pass the master exam.
- Apply for the master license within one year and file insurance to be insured to contract.
- Renew every two years.
Experience and other requirements
Experience. Master: hold a journey license for at least two years and complete 3,750 hours of training under a licensed master plumber. Journey: hold an apprentice license for at least four years, complete 7,500 hours under a master and 32 hours of backflow prevention testing training.
The license to apply for. Master Plumber/Gas Fitter license.
Maryland plumbing exams
Trade exam. Yes. A comprehensive written exam given by PSI. You must send proof of hours, your backflow certification and your driver's license.
Business and law exam. The official pages we read do not say. Check with the board (official site).
What it costs in Maryland
We could not confirm the current fee schedule on an official page. Check with the board before you budget: Maryland State Board of Plumbing, Maryland Department of Labor.
Insurance and bond
Insurance. To contract work, a licensee needs at least $400,000 per occurrence: $300,000 general liability and $100,000 property damage. Umbrella policies do not count, and the Maryland State Board of Plumbing must be the certificate holder.
Bond. The official pages we read do not say. Check with the board (official site).
Renewal and licenses from other states
Renewal. Every two years from the date of issue. Maryland plumbing licenses have no continuing education requirement. A license lapsed more than four years means a new application and exam.
Reciprocity. Reciprocal master or journey licenses for plumbers licensed in Baltimore County, WSSC or DC, and master plumber/gas fitter reciprocity with Delaware.
Good to know in Maryland
- A homeowner may do plumbing in their own home but may not make the final connection to a public or private water or sewer system.
- A passing exam score is good for one year from the exam date.
- Licensees choose an insured to contract status or a not insured status with the board.
After you are licensed
The license lets you take the work. Getting the work is the next job.
- Register the business. If you work under a name other than your own, register it where your state asks (often the Secretary of State, sometimes the county), and keep the name the same on your license, your truck and your invoices.
- Claim your Google Business Profile. It is the listing people see when they search for a plumber near them. Fill in your service area, hours and real photos of your work.
- Put up a website that shows the license. Customers look for it before they call. Koira builds a contractor website for you and keeps it current.
- See where you stand. The free Koira report checks how your business shows up in search and on maps against shops near you.
Where this comes from
Every fact on this page comes from the Maryland State Board of Plumbing, Maryland Department of Labor and the official pages below, checked October 8, 2026. Fees and rules change, so confirm with the board before you file.
More for your trade: how plumbing companies run on Koira.