Cook County's First Installment Property Tax Bills Will Be Month Later Than Normal

LEMONT, IL — The first installment property tax bills will be mailed a month later than normal, after state legislature enacted a one-time-only extension, according to Lemont Township.

Bills are normally mailed around the first of February, and are due by March 1. However, for 2026, bills will be mailed in early March and will be due by April 1.

The extension was given so taxpayers had more time between tax bill payments. The Township said the due date for last year's second installment bills should have been Aug. 1, however, it was delayed to Dec. 15 due to problems with the county's new computer system.

The Lemont Township Assessor's team, as well as other assessors in the Cook County Township Assessors Association, felt that the short gap between bills would have caused financial hardship for many, the Township said.

So, the CCTAA advocated for an extension with Senate President Don Harmon’s office. Officers from Cook County agencies worked on the same issue with members of the Illinois House, according to the Township.