In Minnesota there is no licensing requirements. If you wanted to tomorrow you could start your own company and call yourself an inspector. When trying to find an inspector make sure they are qualified! The following is a list of my qualifications and continuing education courses that I have attended.
I have completely remodeled two houses including; new roof, new siding, new bathrooms, hardwood floors, ceramic tile, plumbing, electrical panels, new decks, new windows, remodeled kitchens, finished two basements, new doors, and on and on... Not one cent was paid to contractors for the work done. Best way to learn it.... do it yourself.