A subcontractor is a specialist hired by a general contractor to perform a specific trade on a construction project. Electricians, plumbers, roofers, drywallers, painters, and HVAC technicians are usually subcontractors. They bring specialized skills, tools, and crews that a general contractor does not keep on staff.

The relationship is contractual. The general contractor holds the contract with the owner. The subcontractor holds a contract with the general contractor. The subcontractor is responsible for the scope, schedule, and quality of their trade. The general contractor coordinates them with other trades and the overall project.

Subcontracting is efficient. It lets a general contractor scale up or down as needed. It lets specialists focus on what they do best. But it also creates coordination challenges. If the electrician and the plumber both need the same wall space at the same time, someone has to wait. Good scheduling prevents that.

Subcontractors are usually licensed and insured. They carry their own liability and workers' compensation. When a subcontractor fails, the general contractor is often the one who has to fix it.