Corporations can now deduct the premiums for income tax purposes. Employees are not taxed on premiums paid by the corporations. Employees are not taxed on benefits paid to them.
Discounts are available for companies paying premiums on multiple employees.
When a covered employee leaves or retires, he can take his policy with him. Although the former employee would then pay his own premiums, he may still get the discounted rates. Coverage can be discriminatory. You can cover key employees without offering coverage to all employees. You could cover management but not administrative personnel, for example.