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Reciprocal Licensing - Plumbing

The Board may issue a reciprocal master or journey license to plumbers who are currently licensed in Baltimore County or WSSC.

To qualify for reciprocation from WSSC or Baltimore County, you must hold BOTH the plumbing and gas portion of the license.

The State Plumbing Board reciprocates with the State of Delaware:
For the Master Plumber/Gasfitter license ONLY, you can apply online or call the State Board of Plumbing for an application.

Individuals who hold a current journey or master gas fitter license from Baltimore County or WSSC may obtain a like state natural gas fitter's license.

Supporting documents to be filed with a reciprocal license application:

  • Verification letter from Baltimore County, the Washington Suburban Sanitary Commission (WSSC) or State of Delaware
  • Natural Gas Fitter verification form
  • Certificate of Insurance (your name must appear on the certificate and the Maryland State Board of Plumbing must be named as the certificate holder)
  • Copy of current license
  • Copy of current master HVACR or master restricted (applicable to master natural gas fitter reciprocal licensing only)
  • Copy of Photo ID or driver’s license
  • Backflow Certification (applicable to master and journey plumbing/gas fitter only)

E-mail your supporting documentation to