Jay, good question. This is actually worth a survey for integrators generally on healthcare, so I'll queue that up.
The 20% retirement package is a SEP IRA. 20% of employees salary is automatically deposited into an IRA account, so for example if the employees salary is $100,000 annually, we would deposit an additional $20,000 in their IRA account. Employee is then free to invest or withdraw those funds as they see fit.
The reason that we can do this is because we have only a limited number of typically more senior employees. By contrast if we had a number of junior technicians, this would be much harder financially to justify both for the retirement benefits and healthcare.
Let me know if I can expand further.