Indiana Code Title 36. Local Government § 36-8-10-8

Sec. 8. A member of the department who becomes sheriff either by election or by appointment shall, upon the expiration of the member's term as sheriff, and upon the member's written application, be appointed by the board to the rank in the department that the member held at the time of the member's election or appointment as sheriff, if there is a vacancy in the department.  However, if the member during the member's tenure of office as sheriff has qualified in accordance with the promotion procedure prescribed by the board in its rules for a rank in the department that is higher than the rank the member previously held, the board shall, upon the expiration of the member's term as sheriff, appoint the member to the rank for which the member has qualified under the promotion procedure if there is a vacancy in that rank.