SUPPORT STAFF BENEFITS Part Time Support Staff Employee Benefits Illinois Municipal Retirement Plan: Employees scheduled to work 600 hours per year (3.5 hours per day for 10 month employees) are enrolled in the Illinois Municipal Retirement Fund (IMRF). TRS - Teachers' Retirement System: Currently Morton School District's Board of Education funds 100% of the Member TRS retirement contribution up to 9.0% (9.8901% compounded) and 0.9% of the professional staff member's salary for the Member THIS fund contribution.