My industry uses something akin to a "collective benefits association" that handles benefits for employees that would work for multiple locations in the same industry. The company pays that association $X/hr for the employee and the benefits are distributed centrally by that association to the employees for all the pay received from multiple companies. This is for people classified as employees, not contractors. The association has to be adequately staffed though because their benefits are pro-rated by employer by work share, and each employer must report those benefits (like vacation pay) to unemployment agencies for taxation. The pro-rating and reporting to employers by the association helps avoid double taxation of unemployment and FICA matching for the employers. Its a lot of work, but it gets the job done and is probably the best solution manageable for employees who are classified as employees and work at multiple locations for multiple employers.