- Alaska Department of Labor and Workforce Development Plumbing and Mechanical Division
- Idaho Division of Building Safety
- Iowa Plumbing and Mechanical Systems Board office
- Kentucky Department Housing Building & Construction (plumbing)
- Massachusetts Board of State Examiners of Plumbers and Gas Fitters
- New Mexico Regulation & Licensing Department (plumbing)
- North Dakota State Plumbing Board
- Oklahoma Construction Industries Board Plumbing Division
- Oregon Licensing Department (plumbing)
- South Dakota State Plumbing Commision
- State of Utah Department of Commerce, Division of Occupational and Professional Licensing
- Vermont Division of Public Safety, Division of Fire Safety
- Virginia Department of Professional and Occupational Regulation
- International Code Council ICC
- National Home Builders Association NAHB
- Mid-Minnesota Home Builders Association
- Grand Traverse Home Builders Association
- Muskegon Home Builders Association
- Traverse City Chamber of Commerce
- IEC Independent Electrical Contractors
- NASCLA National Association of State Contractors Licensing Agencies
Affiliates & Partners
- Home Builders Association of Alabama
- USW/USS GLW Career Development Center
- Michigan Rehabilitation Services
- Michigan Works!
Plumbers Training Institute and its sister schools are subsidiaries of Certified Training Institute.
ATI provides continuing education to licensed architects and landscape architects.
BLTI provides continuing education, prelicensure courses and licensing exam prep for contractors.
CTI provides continuing education and exam preparation courses for pesticide applicators.
RTI provides continuing education and exam preparation courses for real estate professionals.
Engineering Credits provides continuing education for engineering professionals.