How Do You Get a Plumbing License in Maryland?

Yes.

Plumbing is licensed at the state level in Maryland: the Maryland State Board of Plumbing issues the Apprentice, Journey and Master Plumber/Gas Fitter licenses that make up the state's plumbing ladder, and apprentices must be at least 16 to start.

The same board licenses separate Apprentice, Journey and Master Natural Gas Fitters and certifies propane gas fitters, so gas work has its own track on the same board.

Baltimore County and the Washington Suburban Sanitary Commission also issue plumbing credentials the state board reciprocates, which we cover below.

The plumbing ladder has three rungs: Apprentice Plumber/Gas Fitter, Journey Plumber/Gas Fitter and Master Plumber/Gas Fitter.

The apprentice license is the entry rung: at least 16 years old, logging the training hours under a licensed master plumber that count toward the journey license's 7,500-hour requirement.

The journey license is the qualified trade license, defined by its requirements — 4 years holding an apprentice license, 7,500 hours under a licensed master plumber, 32 hours of backflow prevention device testing training and a written exam.

The master license tops the ladder — 2 years holding a journey license, 3,750 more hours under a licensed master plumber and a comprehensive written exam.

A master plumber must carry at least $400,000 per occurrence insurance ($300,000 general liability plus $100,000 property damage), with no umbrella policies accepted, naming the Maryland State Board of Plumbing as certificate holder.

Our research found no separate state plumbing contractor license — the board's requirement pages list only individual licenses — so in what we found, a plumbing business runs on its individually licensed, insured master plumber; confirm the business-side rules with the board.

The apprentice license starts the ladder: you must be at least 16, and the original apprentice license fee is $18.50 under the board's fee schedule updated July 1, 2025.

The journey license requires holding an apprentice license for at least 4 years, 7,500 hours of training under the control and direction of a licensed master plumber, 32 hours of backflow prevention device testing training, and a written exam.

The master license requires holding a journey license for at least 2 years, 3,750 hours under a licensed master plumber, and a comprehensive written exam.

Original license fees on that schedule: Master Plumber/Gas Fitter $87.50, journeyman $43.50, apprentice $18.50.

Apprentices training in a registered Maryland apprenticeship program hold the same board apprentice license — program registration does not replace it.

PSI Examination Services provides all testing for the Maryland State Board of Plumbing.

Candidates upload proof of hours, backflow certification and ID to PSI.

Our research did not confirm what the journey or master exams cover, so check with PSI and the board for the current content outline before you book.

Licenses and certificates the board issues expire two years from the date of issue, so a license is a two-year credential.

Renewal fees run $87.50 for a master, $43.50 for a journeyman and $18.50 for an apprentice.

One deadline matters for apprentices: an apprentice license may be renewed for only two consecutive cycles before the holder must take the journey exam.

Continuing education is not part of renewal for plumbers — the board's CE requirement, 8 hours each calendar year, applies to plumbing inspectors only.

State-to-state reciprocity is narrow: the board reciprocates with Delaware for the Master Plumber/Gas Fitter license only.

The board may also issue a reciprocal master or journey license to plumbers who are currently licensed in Baltimore County, WSSC, or DC — the board's reciprocity page says its WSSC and Baltimore County licensees must hold both the plumbing and gas portions obtained by examination.

If you hold any other state's license, plan to qualify through Maryland's own requirements, and confirm your situation with the board before you rely on it.

The lookup address our research recorded is the Maryland Department of Labor's electronic license search, linked in the resources list on this page.

How it searches — for example, by name, by license number, or both — is not confirmed, so if the search does not settle a license question, confirm it directly with the board.

Baltimore County and the Washington Suburban Sanitary Commission (WSSC) issue their own plumbing credentials.

The state board's link to those local licenses is reciprocity: it may issue a reciprocal master or journey license to plumbers licensed by examination in either body, who must hold both the plumbing and gas portions obtained by examination.

Our research could not verify current WSSC registration details, so if you will work there, check with WSSC or the county before you take the work.

Gas fitting has its own track on the same board: separate Apprentice, Journey and Master Natural Gas Fitter licenses.

A journey natural gas fitter must have acquired 3,750 working hours as an apprentice natural gas fitter over a period of at least two years.

The board also certifies Propane Gas Fitters, which takes NPGA Distribution Systems Operations training or equivalent.

Fees differ from the plumbing side: $150.50 for a Master Natural Gas Fitter and $68.50 for a Journey Natural Gas Fitter as of the July 1, 2025 schedule.

The board's requirements also note that an HVACR master with 2 years of gas-fitting experience can qualify for the Master Natural Gas Fitter license by exam.

Backflow training appeared in our research only as the journey plumber/gas fitter's 32-hour requirement — ask the board whether a separate backflow certification exists.