In the state of Michigan there are two types of licenses for companies that do home repair work.
Smithco Construction is a licensed residential builder. License number 2101154567
A Residential Builder may build a new home from the ground up or may do any kind of repairs regulated under Article 24 of the Occupational Code. The builder may contract for the whole job, but will have to subcontract for plumbing, electrical, and mechanical (heating, ventilation, air conditioning) work to licensed plumbing, electrical and mechanical contractors
Some companies are only M&A contractors
A Maintenance & Alteration (M&A) Contractor is licensed to perform only specific trades and services and may accept contracts only in the trade(s) or craft(s) for which he or she is licensed. The contractor's wall license and pocket card identifies the trades for which the M&A Contractor is licensed. The pocket card contains a letter code that represents the trade or trades in which that contractor is licensed. The M&A trades and their equivalent letter codes are:
Make sure the companies working on your home know what they are doing and are licensed to do so. You don't want a guy who only got state certification to do roofing remodeling your kitchen. Not only could he have limited knowledge of what to do but problems could come up with permits and that could come back to bite you.