105.900.  Employee defined — limitations — tax exempt, when. — 1.  As herein provided, "employee" means any person^*, including elected or appointed officials, receiving compensation from the state, city, county, or other political subdivision for services rendered, including salaried persons.  In no event shall the total of the amount of deferred compensation to be set aside under a deferred compensation program and the employee's nondeferred income for any year exceed the total annual salary or compensation under the existing salary schedule or classification plan applicable to such employee in such year.

  2.  The deferred compensation program established by sections 105.900 to 105.925, shall exist and serve in addition to retirement, pension and benefit systems established by the state or political subdivision.  Any income deferred under such a plan shall continue to be included as regular compensation for the purpose of computing the retirement and pension benefits earned by any employee.  However, any sum deferred under the deferred compensation program shall be exempt from taxation by this state to the same extent as it is exempt from income tax imposed by the United States.