N.Y.C. Admin. Code § 28-408.3.1: § 28-408.3.1 Experience.

All applicants for a master plumber license shall submit satisfactory proof establishing that the applicant:

1. Has at least seven (7) years total experience, within the ten (10) years prior to application, in the installation of plumbing systems and the planning or design of plumbing systems under the direct and continuing supervision of a licensed master plumber in the United States, with at least two (2) years of such experience as a registered journeyman plumber in accordance with the provisions of article 409;

2. Has received a bachelor's degree in mechanical engineering or appropriate engineering technology from an accredited college or university and has at least five (5) years total experience, within the seven (7) years prior to application, in the installation of plumbing systems and the planning or design of plumbing systems under the direct and continuing supervision of a licensed master plumber in the United States, where at least two (2) years of such experience were in New York city;

3. Is an architect or engineer with at least three (3) years of experience, within the five (5) years prior to application, in the installation of plumbing systems and the planning or design of plumbing systems. All required experience must be under the direct and continuing supervision of a licensed master plumber in the United States, and at least one (1) year of such experience must be in New York city;

4. Has at least seven (7) years total experience, within the ten (10) years prior to application, with at least two (2) years of such experience working with installation of plumbing systems and in the planning or design of plumbing systems under the direct and continuing supervision of a licensed master plumber in the United States. The balance of such required experience may be obtained by performing maintenance, replacement and repair plumbing work on existing buildings while in the employ of a city agency under the direct and continuing supervision of a licensed master plumber supervisor employed by the city agency. The two (2) years' experience in the installation of plumbing systems and in the planning or design of plumbing systems set forth above may only be satisfied by working as a registered journeyman plumber; or

5. Has experience as an employee of a government agency, or a private inspection agency or other entity as specified in department rules, whose duties primarily involve the inspection of plumbing work for compliance with the New York city plumbing code and/or other laws relating to the installation, alteration or repair of plumbing systems that shall be credited for fifty percent (50%) of the number of years that he or she has been satisfactorily employed in such duties within the ten (10) year period prior to application, which, however, in no event, shall exceed two and one-half (2.5) years credit of satisfactory experience. The balance of the required seven (7) years must have been obtained by working with installation of plumbing systems and in the planning or design of plumbing systems under the direct and continuing supervision of a licensed master plumber in the United States, except that the requirement of paragraph 1 of this section that an applicant's working experience must have been within the ten (10) year period prior to application shall not apply to such balance of the work experience required pursuant to this paragraph