Do the subcontractors you hire provide a certificate of insurance proving they carry their own workers compensation coverage?  If you are not requesting a certificate for every subcontractor you are putting your company at substantial risk. Many insurance companies and states require a company to include subcontractors under their workers compensation policy if the subcontractor can’t prove they maintain their own coverage.

Depending on the length of the project its a good idea to check during the project period that the coverage is still in force.  While the original certificate may indicate a term of coverage that exceeds the project period, lack of payment or some other factor may cause the policy to be cancelled.

Failure to pay attention to maintaining certificates can result in substantial, unplanned for premium increases.  In the event of injury, the subcontractor may not be covered and your company may be sued to cover medical costs. Both possibilities are something to be avoided.