California to Delaware: master HVAC technician license reciprocity

Delaware issues a person-held Master HVACR license through the Board of Plumbing, Heating, Ventilation, Air Conditioning and Refrigeration Examiners in the Division of Professional Regulation (the electrical trade is regulated by a separate board). A Master HVACR licensee may design, install, service and alter heating, air conditioning, refrigeration, ventilation and process systems including gas piping; a Master HVACR Restricted license covers one specialty (forced-air heating with ventilation and gas piping, hydronic heating with gas piping, commercial hood systems, refrigeration, air conditioning, or gas piping). Employees work under a master's supervision without their own license. A new master needs a journeyman certificate from a federally-registered apprenticeship plus 2 years under a master, or 7 years under a master plus the ABC Delaware Apprenticeship By-Pass exam, then passes the ProV-administered Master HVACR exam (100 questions, 4 hours, open book, 70%, $100) and pays the $173 application fee; a CFC (EPA 608) card is required. Out-of-state masters are licensed by reciprocity without a Delaware exam under 24 Del. C. § 1823: the Board has published that Connecticut and Maryland standards are substantially similar (no experience proof) and that fourteen other jurisdictions are not (7 years of licensed practice required); all other states are evaluated case by case. Licenses renew biennially with 5 hours of continuing education from 2026.

California does not issue a master HVAC or master refrigeration license, and the credential that sits above the (non-existent) journeyman level is a CSLB contractor license in classification C-20 Warm-Air Heating, Ventilating and Air-Conditioning or C-38 Refrigeration. That license is issued to a business (sole owner, partnership, corporation or LLC) and qualified by a named individual rather than held by the mechanic personally, so an out-of-state master HVAC license transfers to nothing unless the holder intends to contract; a master who only wants to work for an employer needs no California license at all. To contract, the qualifying individual must document at least four years of journeyman-level or higher experience within the past 10 years, pay the $450 application fee, pass both the CSLB Law and Business exam and the C-20 (or C-38) trade exam through PSI within 18 months, be fingerprinted, post a $25,000 contractor's bond (plus a $25,000 bond of qualifying individual where applicable), carry workers' compensation or file an exemption, and pay the initial license fee of $200 (sole owner) or $350 (non-sole owner) for a two-year license. CSLB's reciprocity program can waive the trade exam for a contractor who has held an active license in good standing for the previous five years in a classification on the Reciprocal Classifications List: for C-20 the mapped classifications are Arizona C-39, C-39R (as printed), K-39, K-79, L-39 and L-79 Air Conditioning and Refrigeration and Nevada C-1f Heating, Cooling and Circulating Air and C-21 Refrigeration and Air Conditioning; for C-38 they are Arizona L-49 Commercial and Industrial Refrigeration and Nevada C-21a Refrigeration. The Louisiana, Mississippi and North Carolina reciprocity entries cover only general building. Even where reciprocity is granted CSLB retains the right to require the trade exam, decides comparability case by case, and always requires the Law and Business exam, bond, fingerprinting and every other licensure requirement. EPA Section 608 certification is a federal prerequisite for handling refrigerants and is not part of the CSLB application.