Whether you need workers' compensation insurance for contractors depends on your worker classification and state requirements. California requires employers, including construction companies, to carry workers' compensation insurance with even one employee, while Texas doesn't require most private employers to have workers' compensation.
Beyond state requirements, it also depends on whether people working for you are independent contractors or direct employees. This determines what you're legally required to do and how much it could cost you. Misclassifying workers can lead to penalties, back taxes and legal complications.