In virtually every state Workers Compensation insurance is mandatory. Employers are required to carry Workmans Comp Insurance on their employees.
Employers who do not carry Workers Comp for their employees (and may be paying small claims "out of pocket") risk being personally liable for all medical bills from ANY accident in addition to significant governmental fines.
For contractors, having proof of Workers Compensation Insurance is usually required to be a subcontractor with a larger general contractor. Proof of Workmans Comp coverage is provided by a Workers Compensation Certification.
Complete Coverage, Inc. generates certificates the same day they are requested!