35 ILCS 200/3-50
In all counties with 3,000,000 or more inhabitants, the office of county assessor, heretofore created and established, is hereby continued.
The county assessor shall be elected as provided in the general election law, at the general election in 1994 and every fourth year thereafter to hold office for a term of 4 years from the first Monday of December, and until a successor is elected and qualified. Any vacancy in office shall be filled by appointment as provided in the general election law, until the next regular election of county officers when a successor shall be elected for the unexpired term or for the full term as the case may require. The county assessor shall take the oath and give the bond herein required of other assessors and of supervisors of assessments and shall receive such compensation payable from the county treasury in an amount set by the county board. The amount so set shall not be changed during the term for which he or she is elected or appointed. The county assessor shall also have a suitable office to be provided by the county board.
35 ILCS 200/3-50