105 ILCS 5/24-14
As used in this Section, "teaching assignment" means any full-time position that requires licensure under Article 21B of this Code.
A teacher, as defined in Section 24-11 of this Code may resign at any time by obtaining concurrence of the board . During the school term, no teacher may resign , without the concurrence of the board, in order to accept another teaching assignment. Outside of a school term, a resignation submitted by any teacher after the completion of the school year must be submitted in writing to the secretary of the board a minimum of 30 calendar days prior to the first student attendance day of the following school year or else the teacher will be deemed to have resigned during the school term. Any teacher terminating said service not in accordance with this Section may be referred by the board to the State Superintendent of Education. A referral to the State Superintendent for an alleged violation of this Section must include (i) a dated copy of the teacher's resignation letter, (ii) a copy of the reporting district's current school year calendar, (iii) proof of employment for the school year at issue, (iv) documentation showing that the district's board did not accept the teacher's resignation, and (v) evidence that the teacher left the district in order to accept another teaching assignment. If the district intends to submit a referral to the State Superintendent, the district shall submit the referral to the State Superintendent within 10 business days after the board denies acceptance of the resignation. The district shall notify the teacher that it submitted the referral to the State Superintendent within 5 business days after submitting the referral to the State Superintendent. The State Superintendent or his or her designee shall convene an informal evidentiary hearing no later than 90 days after receipt of the required documentation from the school district as required in this Section . The teacher shall receive a written determination from the State Superintendent or his or her designee no later than 14 days after the hearing is completed. If the State Superintendent or his or her designee finds that the teacher resigned during the school term without the concurrence of the board to accept another teaching assignment, the State Superintendent must suspend the teacher's license for one calendar year. In lieu of a hearing and finding, the teacher may agree to a lesser licensure sanction at the discretion of the State Superintendent or his or her designee.
105 ILCS 5/24-14