Yes, you need a statewide plumbing license in Maryland, and it comes from the Maryland State Board of Plumbing, part of the Maryland Department of Labor. You start as an apprentice (age 16 or older), log 7,500 hours over at least 4 years, finish a 32 hour backflow course, and pass the journey exam. After 2 more years and 3,750 hours as a journey plumber, you can test for master.
Who licenses plumbers in Maryland
The Maryland State Board of Plumbing licenses apprentices, journey plumbers, master plumbers, and natural gas fitters. It also certifies propane gas fitters and plumbing inspectors. PSI Examination Services runs the exams.
The law is Title 12 of the Business Occupations and Professions Article. It says you need a Board license to provide plumbing services, or to help provide them, anywhere in the state. The Board’s rules are in COMAR 09.20, and COMAR 09.20.01.01 adopts the most recent International Plumbing Code, International Fuel Gas Code, NFPA 54, and NFPA 58 as the state code.
Requirements change, so confirm with the Maryland State Board of Plumbing before you apply. This page is a plain-English guide, not legal advice.
License types
Here are the tiers on the Board’s license requirements page:
- Apprentice Plumber/Gas Fitter. Your entry license. You must be at least 16. You can only assist, and a master or journey licensee has to be on the jobsite with you.
- Journey Plumber/Gas Fitter. A full working license, but you work under the direction and control of a master plumber.
- Master Plumber/Gas Fitter. The top plumbing license. Only an insured master can contract for plumbing or gas work.
- Natural gas fitter (apprentice, journey, master). A separate track for natural gas work only.
- Propane Gas Fitter certificate. Based on National Propane Gas Association training, an older local license, or equivalent qualifications.
- Plumbing Inspector card. For inspectors working for a local jurisdiction. You need a master or journey license, and you put your master license on inactive status when you become an inspector.
How to become a plumber in Maryland
Here’s the ladder under section 12-302 of the law:
- Get your apprentice license. Apply online through the Board. You need to be 16 or older and working under a licensed master.
- Log 7,500 hours over at least 4 years. The hours must be training under a licensed master plumber. Up to 1,500 hours of approved school study can count toward the total.
- Finish 32 hours of backflow training. You need a Board-approved 32 hour backflow prevention device testing course. The PSI bulletin says it has to be non-expired when you apply to test.
- Pass the journey exam. Then apply for your journey license within a year.
- Go for master. After at least 2 years as a licensed journey plumber and 3,750 hours under a master, you can sit for the master exam.
- Get insured if you’ll contract. Masters who contract must show proof of liability insurance (more below).
Watch the apprentice clock. Apprentices first licensed on or after October 1, 2012, can’t keep renewing forever without taking the journey exam. The Board’s fee page says two consecutive renewal cycles. The statute (section 12-308.1) says no more than three consecutive terms, plus an extra 2 year term for each failed journey exam. Ask the Board which applies to you, and plan to test early.
The natural gas fitter path
A journey natural gas fitter needs 3,750 hours as an apprentice natural gas fitter over at least 2 years, an approved training course, and the exam. Master has three routes, one through a Maryland HVACR master license.
Exams
You must pass the PSI exam before you apply for a journey or master license. Per the Board’s exam page, PSI tests in Baltimore, College Park, Hagerstown, Lanham, and Salisbury. Here’s what the PSI candidate bulletin (updated 9/1/2024) says:
- Plumber/Gas Fitter exams. Master and journey are each 100 questions in 240 minutes.
- Natural gas fitter exams. Master and journey are each 40 questions in 90 minutes.
- Passing score. 70% on every exam.
- Open book. Bring your own 2018 International Plumbing Code, 2018 International Fuel Gas Code, Mathematics for Plumbers and Pipefitters, a backflow text, and OSHA 29 CFR 1926. Tabs and highlighting are fine.
- Retakes. You have to wait at least 30 days and pay again.
- Score life. The Board says a passing score is good for one year to apply for your license.
Register online at PSI’s site (program code “mdplu”) and upload proof of hours, your backflow certificate, and your driver’s license. Since March 31, 2025, PSI doesn’t take applications by mail, fax, or email.
Renewal
Per the Board’s renewal page, licenses expire two years from the date of issue. You renew online after a notice about 60 days before.
- No CE for plumbers. Maryland doesn’t require continuing education to keep a plumbing license. Inspector card holders need 8 hours every calendar year.
- Lapsed up to 4 years. The Board must reinstate you if you apply within 4 years and meet the renewal rules.
- Lapsed over 4 years. You file a new application and pass the exam again.
One note: the statute’s default is that licenses expire on May 1 of odd-numbered years, but it lets the state stagger them. The Board now uses two years from issue, so go by the date on your license.
Cost
These fees come from the Board’s Forms and Fees page (updated July 1, 2025) and the PSI bulletin:
- Apprentice Plumber/Gas Fitter: $18.50 license, $18.50 renewal.
- Journey Plumber/Gas Fitter: $65 PSI exam, $43.50 license, $43.50 renewal.
- Master Plumber/Gas Fitter: $65 PSI exam, $87.50 license, $87.50 renewal.
- Apprentice Natural Gas Fitter: $18.50 license, $18.50 renewal.
- Journey Natural Gas Fitter: $25 PSI exam, $68.50 license, $31.50 renewal.
- Master Natural Gas Fitter: $65 PSI exam, $150.50 license, $43.50 renewal.
- Propane Gas Fitter certificate: $25 application, $31.50 license.
Renewals are every two years. PSI fees are non-refundable. The Board doesn’t list a late or reinstatement fee, so ask. Backflow course and code book costs are set by the seller.
Master insurance
Under section 12-501, a master who contracts needs liability coverage, including completed operations, of at least $300,000 for bodily injury and $100,000 for property damage. The Board’s FAQ adds that umbrella policies don’t count toward the minimum and the Board must be the certificate holder. Journey plumbers and apprentices don’t need their own policy.
Reciprocity
Maryland has a short list. Per the Board’s reciprocal licensing page:
- Baltimore County and WSSC. Master or journey plumbers can get a like state license. Your local license must include both the plumbing and gas parts and must have been earned by exam. Gas fitter licenses from these two also transfer.
- Delaware. Master Plumber/Gas Fitter only. There’s no journey reciprocity with Delaware.
- District of Columbia. Listed on the reciprocity page for master and journey plumbers, but the Board’s FAQ names only Delaware, WSSC, and Baltimore County. Ask the Board before you count on it.
You’ll send a verification letter, backflow certificate, license copy, and photo ID. Masters also need a certificate of insurance naming the Board. The law lets the Board waive the exam for other states only by majority vote and only if that state returns the favor. A one-time Virginia waiver for military relocations ended July 1, 2012. See our plumbing license reciprocity guide for more.
How to apply
- Apprentice. Use the “Original Apprentice Licenses” link on the Board’s apply page.
- Journey or master. Get approved by PSI and pass the exam first, then apply online for the license within a year.
- Masters who contract. Include your certificate of insurance.
- Need help? Call the Board Administrator at 410-230-6379, or licensing at 410-230-6231. The office is at 100 S. Charles Street, Tower I, Baltimore.
Doing plumbing without a license can mean up to $100 per day and 6 months in jail, or a $5,000 fine per violation.
FAQ
How long does it take to get a plumbing license in Maryland?
At least 4 years to journey, and at least 2 more years to master.
How much does a Maryland plumbing license cost?
Journey is a $65 exam plus a $43.50 license. Master is a $65 exam plus an $87.50 license.
Do Maryland plumbers need continuing education?
No. Only plumbing inspectors need CE, 8 hours a year.
Does Maryland accept a Virginia plumbing license?
Not automatically. Virginia isn’t on the Board’s reciprocity list, so plan on testing.
Next steps
If you’re starting out, find a master plumber to work under, get your apprentice license, and book your 32 hour backflow course well before your 4 years are up. To compare Maryland with other states, see our plumbing license by state page, the full plumbing license guide, and plumbing license cost by state. Working near the border? Check the Virginia plumbing license and Delaware plumbing license pages. Once you’re an insured master ready to run your own shop, read how to start a plumbing business.
