In April 2026, the Missouri House of Representatives passed SB 1066. This bill would have made numerous changes to Missouri’s property tax system, including the separation of residential and commercial property tax subclasses and the institution of an inspection requirement for commercial properties with assessment increases over 15%. However, the Missouri Senate was unable to pass the bill over disagreements with some of the provisions, and the bill died on May 16 as the 2026 legislative session came to a close.

SB 1066 intended to address unintended consequences of the Hancock Amendment, a 1980 constitutional provision that requires a rollback of tax rates if property values rise faster than inflation. The Hancock Amendment considers property tax revenue as aggregated between all property subclasses, meaning that if one subclass increases much faster than the others, the property tax rollback threshold can still be unmet. The provisions of SB 1066, particularly the siloing of property tax subclasses like residential and commercial, were spurred by increasing residential assessments in the Kansas City area.

Given the bipartisan support for the bill in both chambers, this legislation will likely return in the 2027 legislative session. Because the current system allows for rollbacks of commercial property taxes in response to hot residential markets, this bill could have a meaningful impact on property taxation for NAIOP members. NAIOP will continue to monitor this legislation next year.