Residential and commercial contractors all need construction contractor insurance. This is not a negotiable requirement. It will often spell the difference between getting and losing a contract.
Any party who contracts services to others needs contractor insurance. This is required when contracting services to the government on the federal, state or city level. It is also most often required by private entities from contractors.
In effect, contractor insurance protects all parties involved in a contract. Those who hired the contractor are assured that any damage or injury on persons or property caused by the contractors work will be paid for by the insurance. The contractor is assured that he will not have to pay for claims on such damage or injury from his own pocket. It also protects him in case he is wrongfully sued.