In the state of Kansas where the towns are controlled by the League of Muniscipalities. There is a license in every major town over a certain amount of population. Which is why many contractors don’t do work in other town or regions of the state. Not to be confused with other towns and what they require or don’t.
The home owner is not required to to be licensed as he\she lives at the address. Moving a wall, adding or removing electrical and plumbing can all be done by the home owner unless they are a zone county or in a city. Yet little items like switch’s, receptacle replacements, and lights replacements can be done by the home owner. With no regards to zoning, city or state license’s.
I don’t speak for all states. Please check with your city, or county offices for any permits needed for the work you plan on doing. Some counties can enforce a tear down order if no permits was pulled and something was built without approval.