Delaware to Maryland: master plumber license reciprocity
Maryland has a reciprocity agreement with Delaware: a Delaware master plumber can get a Maryland license without retaking the trade exam.
Reference only, not legal advice. Rules change; confirm with the licensing board before you apply. Full disclaimer.
Reciprocal Master Plumber/Gas Fitter license from Delaware (master only)
A signed state-to-state agreement. The trade exam is waived; you apply, prove your history, and pay the fee.
The Board's reciprocal-license page states reciprocity with Delaware is available for Master Plumber/Gas Fitter only. A Delaware Master Plumber files the reciprocal application with a verification letter from Delaware DPR, backflow certification, a copy of the current Delaware license, photo ID, and a certificate of insurance naming the Maryland Board as certificate holder, and pays the $87.50 original license fee. The PSI trade exam is not required. Delaware journeymen are not on this path.
Delaware plumbing journeyman is None (Delaware issues Master Plumber only). Confirm with both boards whether a Delaware HVACR-only license qualifies; this row is for Delaware Master Plumber.
At a glance
- Trade exam
- Waived
- Law / code exam
- Not required
- Agreement
- Active
What you must already have
- Your Delaware license must be active and in good standing.
- Verification letter from Delaware DPR, backflow certification, current license, photo ID, and certificate of insurance with the Board as certificate holder
What you'll do to get licensed in Maryland
- 1License fee. Pay the license or certificate fee ($87.50). Original Master Plumber/Gas Fitter license fee, updated July 1, 2025.
- 2Insurance. Carry the required insurance. Certificate of insurance: general liability of at least $300,000 and property damage of at least $100,000; Board as certificate holder; no umbrella.
- 3Other. Verification letter from the issuing board, backflow certification, copy of the current license, and photo ID.
Published fees on this path total $87.50, excluding exam-vendor fees, bonds, and insurance.
What you'll need to buy or arrange
Liability insurance
Some states require proof of general liability or workers' compensation coverage at licensing time.
- Insurance
How Maryland licenses master plumbers
Maryland master plumber · “Master Plumber/Gas Fitter”
State license plus local requirements
Issued by Maryland State Board of Plumbing (Department of Labor)
Maryland issues a statewide Master Plumber/Gas Fitter license through the State Board of Plumbing. By statute a master plumber is licensed to provide plumbing services and natural gas services. Qualification on the Board's License Requirements page is two years as a journey plumber plus 3,750 hours of work as a journey plumber under a master, then the PSI master exam. The original Master Plumber/Gas Fitter license fee is $87.50 (updated July 1, 2025; renewal is also $87.50). Masters must carry general liability of at least $300,000 and property damage of at least $100,000 ($400,000 per occurrence), with the Board named as certificate holder; umbrella policies are not accepted. Reciprocal Master Plumber/Gas Fitter licenses are issued to holders licensed by the District of Columbia, Delaware (master only), WSSC, or Baltimore County (WSSC and Baltimore County applicants must hold both plumbing and gas licenses obtained by examination).
How local licensing works in Maryland
Same territorial split as the journeyman level: the State Board license is not the license for Baltimore County or for WSSC territory in Montgomery and Prince George's Counties. Those jurisdictions license plumbers separately and enforce their own plumbing codes. A master who will contract in WSSC territory needs the WSSC plumber license; work only in Baltimore County needs the county license. Propane-gas-fitter certificates from the State Board are valid in the entire state. The reciprocal-license page states the Board may issue a State master plumber license to a person already licensed by WSSC or Baltimore County if that person holds both plumbing and gas licenses obtained by examination.
- Washington Suburban Sanitary Commission (Montgomery County)
- Washington Suburban Sanitary Commission (Prince George's County)
- Baltimore County
Common questions
- Do I have to take the Maryland master plumber exam if I'm licensed in Delaware?
- No. The trade exam is waived on this path under the agreement with Delaware.
- What does it cost to get a Maryland master plumber license from Delaware?
- Published fees on this path total $87.50, not counting exam vendor fees or bonds.
- Does it work the other way, from Maryland to Delaware?
- Not necessarily. Reciprocity is directed. Going from Maryland to Delaware, the mechanism is endorsement.
Sources
- Md. Code, Business Occupations and Professions §12-101 - Definitions (State Board of Plumbing licenses) · Md. Code, Bus. Occ. & Prof. §12-101 · Maryland General Assembly · Statute · verified September 16, 2026
- Maryland Department of Labor - Division of Occupational and Professional Licensing (boards index) · Maryland Department of Labor, Division of Occupational and Professional Licensing · Agency Page · verified September 16, 2026
- Maryland State Board of Plumbing - Taking the Exam (PSI) · Maryland Department of Labor, Division of Occupational and Professional Licensing · Agency Page · verified September 16, 2026
- Maryland State Board of Plumbing - Forms and Fees (updated July 1, 2025) · Maryland Department of Labor, Division of Occupational and Professional Licensing · Agency Page · verified September 16, 2026
- Maryland State Board of Plumbing - Home · Md. Code, Bus. Occ. & Prof. Title 12 · Maryland Department of Labor, Division of Occupational and Professional Licensing · Agency Page · verified September 16, 2026
- Maryland State Board of Plumbing - Insurance Requirements · Maryland Department of Labor, Division of Occupational and Professional Licensing · Agency Page · verified September 16, 2026
- Maryland State Board of Plumbing - Licensing Applications · Maryland Department of Labor, Division of Occupational and Professional Licensing · Agency Page · verified September 16, 2026
- Maryland State Board of Plumbing - Apply for a Reciprocal License · Maryland Department of Labor, Division of Occupational and Professional Licensing · Agency Page · verified September 16, 2026
- Maryland State Board of Plumbing - License Requirements · Maryland Department of Labor, Division of Occupational and Professional Licensing · Agency Page · verified September 16, 2026
Verified dates are when a person last opened each source and confirmed the facts above. Cite the board, not us.