Is a work truck ie electrician plumber dog groomer a commercial vehicle?

Classifications of such vehicles under 26,000 lbs. GVWR vary between states. Any vehicle being used for a commercial purpose is, technically, a commercial vehicle, but not necessarily as far as the FMCSR is concerned. The FMCSR would not consider a pickup a commercial vehicle, unless it was carrying quantities of hazardous materials which required placards to be displayed, for example.