Large businesses should employ a "linked" Healthcare Reimbursement Arrangement (HRA). Here is how it works. Let's say you have a group insurance plan that offers a $1,000 deductible for your employees. With a linked HRA, the business adjusts its group policy to a $5,000 deductible (or higher). However, they maintain the lower deductible for their employees, essentially self insurring the amount between the deductibles.
When an employee hits the $1,000 deductible, the business reimburses the employee for out of pocket expenses until the higher deductible is reached.