You are not required to provide health insurance for your employees. If you do, there are state and federal regulations that apply.
 
The rules vary depending on the size of your company. Size is determined differently at the state and federal level.
 
To determine size, the State of Oregon counts the total number of employees working 17.5 hours per week on a regular basis and includes the owners.
 
The Federal Government counts the total number of all employees regardless of hours worked and excludes owners to determine size.

This employee count is ONLY used to determine which set of rules apply.
It does NOT require you to cover all the employees included in the count.