The Illinois Class 6b application is a tax incentive program that provides property tax abatement for newly constructed or substantially rehabilitated commercial, industrial, or mixed-use real estate projects in economically depressed areas. The program is administered by the Illinois Department of Commerce and Economic Opportunity. Eligible projects may receive a property tax abatement of up to 12 years, with the abatement declining annually over the course of the abatement period. The two types of Illinois Class 6b applications are New Construction and Substantial Rehabilitation. The New Construction application is for projects that involve the construction of new commercial or industrial buildings, or the construction of a mixed-use building that includes both commercial and residential components. The Substantial Rehabilitation application is for projects that involve the substantial rehabilitation of existing commercial or industrial buildings, or the substantial rehabilitation of a mixed-use building that includes both commercial and residential components.