(65 ILCS 5/3.1-10-51)
    Sec. 3.1-10-51. Vacancies in municipalities with a population of 500,000 or more.
    (a) Events upon which an elective office in a municipality of 500,000 or more shall become vacant:
        (1) A municipal officer may resign from office. A
    
vacancy occurs in an office by reason of resignation, failure to elect or qualify (in which case the incumbent shall remain in office until the vacancy is filled), death, permanent physical or mental disability rendering the person incapable of performing the duties of his or her office, conviction of a disqualifying crime, abandonment of office, removal from office, or removal of residence from the municipality or, in the case of an alderman of a ward, removal of residence from the ward.
        (2) An admission of guilt of a criminal offense that
    
would, upon conviction, disqualify the municipal officer from holding that office, in the form of a written agreement with State or federal prosecutors to plead guilty to a felony, bribery, perjury, or other infamous crime under State or federal law, shall constitute a resignation from that office, effective at the time the plea agreement is made. For purposes of this Section, a conviction for an offense that disqualifies the municipal officer from holding that office occurs on the date of the return of a guilty verdict or, in the case of a trial by the court, the entry of a finding of guilt.
        (3) Owing a debt to the municipality. A vacancy
    
occurs if a municipal official fails to pay a debt to a municipality in which the official has been elected or appointed to an elected position subject to the following:
            (A) Before a vacancy may occur under this
        
paragraph (3), the municipal clerk shall deliver, by personal service, a written notice to the municipal official that (i) the municipal official is in arrears of a debt to the municipality, (ii) that municipal official must either pay or contest the debt within 30 days after receipt of the notice or the municipal official will be disqualified and his or her office vacated, and (iii) if the municipal official chooses to contest the debt, the municipal official must provide written notice to the municipal clerk of the contesting of the debt. A copy of the notice, and the notice to contest, shall also be mailed by the municipal clerk to the appointed municipal attorney by certified mail. If the municipal clerk is the municipal official indebted to the municipality, the mayor or president of the municipality shall assume the duties of the municipal clerk required under this paragraph (3).
            (B) In the event that the municipal official
        
chooses to contest the debt, a hearing shall be held within 30 days of the municipal clerk's receipt of the written notice of contest from the municipal official. An appointed municipal hearing officer shall preside over the hearing, and shall hear testimony and accept evidence relevant to the existence of the debt owed by the municipal officer to the municipality.
            (C) Upon the conclusion of the hearing, the
        
hearing officer shall make a determination on the basis of the evidence presented as to whether or not the municipal official is in arrears of a debt to the municipality. The determination shall be in writing and shall be designated as findings, decision, and order. The findings, decision, and order shall include: (i) the hearing officer's findings of fact; (ii) a decision of whether or not the municipal official is in arrears of a debt to the municipality based upon the findings of fact; and (iii) an order that either directs the municipal official to pay the debt within 30 days or be disqualified and his or her office vacated or dismisses the matter if a debt owed to the municipality is not proved. A copy of the hearing officer's written determination shall be served upon the municipal official in open proceedings before the hearing officer. If the municipal official does not appear for receipt of the written determination, the written determination shall be deemed to have been served on the municipal official on the date when a copy of the written determination is personally served on the municipal official or on the date when a copy of the written determination is deposited in the United States mail, postage prepaid, addressed to the municipal official at the address on record in the files of the municipality.
            (D) A municipal official aggrieved by the
        
determination of a hearing officer may secure judicial review of such determination in the circuit court of the county in which the hearing was held. The municipal official seeking judicial review must file a petition with the clerk of the court and must serve a copy of the petition upon the municipality by registered or certified mail within 5 days after service of the determination of the hearing officer. The petition shall contain a brief statement of the reasons why the determination of the hearing officer should be reversed. The municipal official shall file proof of service with the clerk of the court. No answer to the petition need be filed, but the municipality shall cause the record of proceedings before the hearing officer to be filed with the clerk of the court on or before the date of the hearing on the petition or as ordered by the court. The court shall set the matter for hearing to be held within 30 days after the filing of the petition and shall make its decision promptly after such hearing.
            (E) If a municipal official chooses to pay the
        
debt, or is ordered to pay the debt after the hearing, the municipal official must present proof of payment to the municipal clerk that the debt was paid in full, and, if applicable, within the required time period as ordered by a hearing officer.
            (F) A municipal official will be disqualified and
        
his or her office vacated pursuant to this paragraph (3) on the later of the following times the municipal official: (i) fails to pay or contest the debt within 30 days of the municipal official's receipt of the notice of the debt; (ii) fails to pay the debt within 30 days after being served with a written determination under subparagraph (C) ordering the municipal official to pay the debt; or (iii) fails to pay the debt within 30 days after being served with a decision pursuant to subparagraph (D) upholding a hearing officer's determination that the municipal officer has failed to pay a debt owed to a municipality.
            (G) For purposes of this paragraph, a "debt"
        
shall mean an arrearage in a definitely ascertainable and quantifiable amount after service of written notice thereof, in the payment of any indebtedness due to the municipality, which has been adjudicated before a tribunal with jurisdiction over the matter. A municipal official is considered in arrears of a debt to a municipality if a debt is more than 30 days overdue from the date the debt was due.
    (b) If a vacancy occurs in an elective municipal office with a 4-year term and there remains an unexpired portion of the term of at least 28 months, and the vacancy occurs at least 130 days before the general municipal election next scheduled under the general election law, then the vacancy shall be filled for the remainder of the term at that general municipal election. Whenever an election is held for this purpose, the municipal clerk shall certify the office to be filled and the candidates for the office to the proper election authorities as provided in the general election law. If the vacancy is in the office of mayor, the city council shall elect one of their members acting mayor. The acting mayor shall perform the duties and possess all the rights and powers of the mayor until a successor to fill the vacancy has been elected and has qualified. If the vacancy is in any other elective municipal office, then until the office is filled by election, the mayor shall appoint a qualified person to the office subject to the advice and consent of the city council.
    (c) If a vacancy occurs later than the time provided in subsection (b) in a 4-year term, a vacancy in the office of mayor shall be filled by the corporate authorities electing one of their members acting mayor. The acting mayor shall perform the duties and possess all the rights and powers of the mayor until a mayor is elected at the next general municipal election and has qualified. A vacancy occurring later than the time provided in subsection (b) in a 4-year term in any elective office other than mayor shall be filled by appointment by the mayor, with the advice and consent of the corporate authorities.
    (d) A municipal officer appointed or elected under this Section shall hold office until the officer's successor is elected and has qualified.
    (e) An appointment to fill a vacancy in the office of alderman shall be made within 60 days after the vacancy occurs. The requirement that an appointment be made within 60 days is an exclusive power and function of the State and is a denial and limitation under Article VII, Section 6, subsection (h) of the Illinois Constitution of the power of a home rule municipality to require that an appointment be made within a different period after the vacancy occurs.
    (f) This Section applies only to municipalities with a population of 500,000 or more.
(Source: P.A. 99-449, eff. 8-24-15.)