The Cook County Assessor’s Office supports HB 860, the Data Modernization Bill, a significant legislative step toward meaningful property tax reform.

Our office is charged with determining the market price of 1.9 million parcels in Cook County. Accurate assessments of income-producing properties like office buildings, apartments and storefronts depend on timely, accurate data about income, expenses and vacancies.

HB860 will ensure that property tax assessments of income-producing properties are based on current data, increasing predictability and accuracy. …

On March 2nd, 2021, Assessor Fritz Kaegi spoke to the City Club of Chicago about the operations of the Cook County Assessor’s Office and offered a preview at the priorities for the year ahead.

In this presentation, Assessor Kaegi gave a progress report on the technological modernization of the office, the restoration of fairness in assessments, and his continued dedication to transparency.

The text and visuals below reflect the presentation as it was prepared for delivery. A video of the speech and the Q&A can be viewed here. An audio-only version is available here.

Thanks for starting us off here…

If you agree with me that Black Lives Matter and that dismantling inequality is important, we must continue to fix inequities in all aspects of our property tax system.

Cook County is in the midst of commemorating Racial Equity Week by examining the disparities of the past and dedicating itself to a more equitable future. I commend Cook County Board President Toni Preckwinkle for leading this discussion each year.

As Cook County’s Assessor, my job is to value the 1.8 million properties in Cook County fairly, without bias or favoritism, by holding up a mirror to the market. While the…

In the past month, some real estate market participants have sent letters of concern to elected officials and local news outlets, suggesting investment in downtown Chicago is in danger because of market-value-based commercial assessments. They have also called for our office to “pause” Cook County’s triennial assessment process and to make changes to property classification rates.

In response, Cook County Assessor Fritz Kaegi wrote the following open letter to everyone with interest in the vitality of our area’s residential and commercial real estate markets.


I want to ensure everyone sees Cook County both as a community where homeowners can…

An image of floodplains in Wilmette, IL which is located in New Trier Township

The Cook County Assessor’s Office recently added FEMA floodplain data to its assessment models.

What this means: our Office is now able to quantify how much a home’s property value is affected by being on a floodplain, and can use that information to produce more accurate property values for homes that are and aren’t on a floodplain.

To explain this change to staff, we sent the following note. In the interest of transparency and providing additional information to the public about our work, we are posting the note publicly below.

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Improving our data and modeling…

Don’t do this.

Links and text last updated on June 26th, 2020.

The Cook County Treasurer just mailed out second-installment property tax bills for all of Cook County. Many taxpayers have questions ranging from missing exemptions and incorrect information to how appeals affect their tax bills.

Due to COVID-19, our offices have been closed to the public. We have moved all our services online at our website. We are also offering video tutorials on Facebook.

To make it as convenient as possible for you to get the answers you need, we’ve created a list of Frequently Asked Questions and Answers on the Cook…

Let’s give a hand to the IAAO for creating a kinda cool version of the Chicago skyline for the cover of its report.

You’ve likely seen a few stories about an audit conducted by the International Association of Assessing Officers, the global pros at assessments. We requested this audit because we are dedicated to reforming this office.

There’s a lot in the report. So here are the primary recommendations:

1. Acquire high-quality data.

Without better data on residential characteristics (rooms, housing type, unique features etc.) or better commercial data on rent, income, and expenses, we won’t achieve our goal of fair and accurate assessments.

To improve our commercial data, we need to pass a bill in Springfield: SB 1379, the Data Modernization Bill.

Assessor Fritz Kaegi, a Chi Hack Night attendee, and Chief Data Officer Rob Ross publish the CCAO’s code and data models live at Chi Hack Night on April 17th, 2019.

As part of our commitment to transparency, The Cook County Assessor’s Office is releasing the final report on our 100 Day Plan. This is the second and final update, which covers all the departments of the Cook County Assessor’s Office (CCAO) with a focus on changes and accomplishments since our 50 Day Update, published in January.


For each department, the CCAO lists highlights of the past 50 days as well as future goals.

At the end of the narrative update is an appendix of internal documents developed by the CCAO leadership team to track our progress…

By Robert Ross
Chief Data Officer, Cook County Assessor’s Office

Rob Ross, Chief Data Officer with the Cook County Assessor’s Office discusses the residential assessment modeling used by the CCAO during a presentation at Chi Hack Night on April 16th, 2019.

Announcing that a County Property Tax Assessor is releasing the source code for their Computer Assisted Mass Appraisal system is a bit like saying you prefer Star Wars to Star Trek; 99% of your audience will be confused and bored while 1% will be apoplectic.

Last night, in front of a packed, sold-out crowd at Chi Hack Night–the city’s weekly gathering of coders journalists, academics, and civic technologists, the Cook County Assessor’s Office unveiled an unprecedented transparency initiative, and it matters far more than your preference in science fiction.


As part of our commitment to transparency, we promised updates to our 100 Day Plan. This is the first of those updates and covers all the departments of the Cook County Assessor’s Office with a focus on changes which started on Day One.

Today marks the halfway point of our 100 Day Plan. Our next update will be published at the conclusion of our first 100 days. It will include accomplishments from that first 100 days as well as next steps we will take on the rest of our plan.

Cook County Assessor Fritz Kaegi is sworn in as Cook County Assessor on Monday, December 3rd, 2018 by Chief of Staff Sarah Garza Resnick, a notary public and former Chief of Staff to former Cook County Clerk David Orr.


Most of our first month was spent…

Cook County Assessor

We are responsible for setting uniform and accurate values for 1.8 million parcels of Cook County property in a fair, ethical and transparent way.

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