65 ILCS 5/7-3-6.2
Notwithstanding any other provision of this Code, the owner or owners of record of a split residential lot may disconnect a portion of the lot which (i) is a residentially zoned and platted lot currently lying partially within the corporate limits of and governed by 2 or more municipalities or lying within the unincorporated area of a county and also within the corporate limits of one or more municipalities, and contains less than 20 acres; (ii) is located on the border of the municipality; and (iii) if disconnected, will not result in the isolation of any part of the municipality from the remainder of the municipality. The owner or owners seeking to disconnect a portion of a split lot from a municipality must petition the court in the manner provided in Section 7-3-6 of this Code. In determining whether a lot shall be disconnected under this Section, the court may consider the following: (i) if disconnected, the growth prospects and planning and zoning ordinances, if any, of the municipality will not be unreasonably disrupted; (ii) if disconnected, no substantial disruption will result to existing municipal service facilities, such as, but not limited to, sewer systems, street lighting, water mains, garbage collection, and fire protection; and (iii) if disconnected, the municipality will not be unduly harmed through loss of tax revenue in the future.
An area of land, or any part thereof, disconnected under the provisions of this Section from a municipality which was incorporated at least 2 years prior to the date of the filing of the petition for disconnection shall not be subdivided into lots or blocks within one year from the date of disconnection. A plat of any such proposed subdivision shall not be accepted for recording within such one-year period, unless the land comprising such proposed subdivision shall have been thereafter annexed into a municipality.
65 ILCS 5/7-3-6.2