With the Cook County First Installment property tax deadline fast approaching on April 1, 2026, local digital hub Oak Park Expert has released a critical resource guide to help Village residents navigate a unique and potentially confusing tax year. Traditionally due in early March, the 2026 First Installment deadline was extended to April 1st following previous administrative shifts at the county level. Because the First Installment is calculated as a flat 55% of the prior year’s total bill, it does not