Special Assessments

A special assessment is a charge to owners of a property immediately benefiting from a local infrastructure project such as the construction or maintenance of roads, sidewalks, sewer lines, etc. They are considered to be liens against the property and are linked to the property itself; regardless of ownership. A lien is a legal claim that an asset or property is collateral against a debt. Special assessments are billed during the year and become part of the property tax bill if unpaid.

While the City covers the vast majority of costs associated with public improvement projects, the properties immediately adjacent to infrastructure improvement projects will benefit the most. Special assessments are used to help cover a small portion of the costs associated with those projects.

Estimating Assessments

road reconstruction
How much you owe depends on the project and your property. Not all work done during a public works improvement project is assessed to the adjacent properties and the assessments do not cover the full cost of the improvements.

Assessment values will vary from property to property. The City’s standard assessment policy bases the calculation of the assessment on the street frontage for all adjacent properties.  Frontages may vary from property to property, so this will result in some differences in the assessment amounts.  Additionally, some items, such as driveway aprons and sanitary sewer laterals, are specifically measured for each property, and some items will vary in size depending on the conditions at each property.

Notification and Communication

The first you hear about an assessment project will likely be in the form of a letter or post card informing you about a planned project in your area. Often this will include a notice of a public information meeting where you can provide feedback during the early planning stages of a project.

The project engineer and any other staff involved in the project, as well as their phone and email contact information, are listed on the Facts and Details sheet included in your assessment mailing, or on the project website.

Once the preliminary project plans are ready, the Engineering Division sends assessment letters to all of the property owners in a project area. This letter includes a breakdown of the charge(s) for the project, called a preliminary schedule of assessments, which estimates your charges for the project based on the planned work. Since plans and project costs can change, the final assessment may end up being different than the initial estimate. Our engineers try to consider all contingencies in their estimates so that property owners end up owing no more than the original estimate. In rare cases the final estimate can end up being more than the initial estimate, but this is typically the result of additional work requested by the property owner.

If property owners decide that they want additional Public Works improvements with the project benefiting their property, they can sign a waiver of special assessments for the additional work requested. This most often happens when there are future plans for a property that result in needing additional work (additional sewer laterals, private storm hookups, etc.).

The full schedule of assessments for every property included in the special assessment district (all properties immediately impacted by the project) can be found on the project webpage. You can also contact Engineering staff at (608) 266-4751 or ENAdmin@cityofmadison.com to be sent a physical copy of the full schedule.
Property owners will receive letters as the project works its way through the city approval process with public hearings at the Board of Public Works and Common Council. Once the project is approved you will also receive a letter from the Finance Department describing the payment process. That letter is not a bill.

Paying a Special Assessment

You will not be charged until after the project has finished construction, although you can make payments as soon as the preliminary assessment has been processed by the Finance Office.
Once construction concludes, Engineering staff measures the final amounts of the assessable items identified for the project. These final measurements are used to calculate the final assessment amount. The final assessment invoice is then sent to property owners, typically in the summer following construction; for example, for a construction project where work is completed in 2022, the final assessment is sent in the summer of 2023.
Property owners have the option to pay in a single lump sum or over installments at the interest rate applied at the time of the estimated assessment mailing. Predominantly, assessments need to be paid off in 8 years. On some projects, typically ones that have higher than normal estimated assessments, an alder can request a 15 year payment plan.
You can figure out your annual payment by using our calculator. You will need to know your assessment total, your interest rate, and the payback timeline (8 or 15 years). This information is included on the Assessor’s Office website Property Search results under Special Assessment and in the assessment mailing sent to each property owner (see Notification & Communication). You can find a copy of the mailing material on that project’s webpage.


The tax roll and interest is calculated based on the outstanding balance at the end of the business day on October 31st each year. This means that no interest is applied if the balance is paid in full on October 31st, or earlier, of the first year. For the first year, interest is prorated based on when the assessment was finalized.


When selling a property, a common requirement is for all assessments to be paid in full, including preliminary assessments. If a preliminary assessment is paid in full and the subsequent final assessment is less, a refund will be issued. If you need to pay a preliminary assessment as per terms of your property sale, please provide forwarding contact information with your payment so that our Finance department can issue any potential refunds to you. If this information is not provided, any refunds will be issued to the property owner of record at the time the final assessments are approved.

Checking Your Balance

You can check how much is left on your special assessment by going to the Assessor’s Office webpage, looking up your property, and going to the Special Assessment tab. If you have any outstanding balance on a special assessment, the following information will be listed:
  • Assessment/Charge Name*
  • Year Assessment was Charged (not the year work was completed)
  • Interest Rate
  • Original Assessment Amount
  • Outstanding Principal
  • Type (Final, Preliminary, Deferred)
*A single project can result in multiple charges because there are different accounts involved for different work (street improvements, sanitary sewer, storm sewer, etc.). Each charge has a breakdown showing the balance due, annual payment, annual interest, and taxroll amount. This breakdown also includes the project name from where the charge originated.

Making a Payment

Annual installments of the special assessment plus interest will be included on your property tax bill. If you wish to make a payment before then, all special assessment payments are made through the City Treasurer’s Office.
You can pay by credit card by calling (608) 266-4771. Have your special assessment invoice on hand so they can pull up your information.
Checks should be made out to City of Madison – Treasurer and mailed with a copy of your special assessment invoice to:
City of Madison – Treasurer
210 Martin Luther King Jr. Blvd., Room 107
Madison, WI 53703
Payments can also be made in person at the Treasurer’s Office, address listed above. Having your invoice with you will speed up the look up process.

Points of Contact

For questions about the project design or construction, contact the project engineer and any other staff involved in the project. Their contact information can be found on that specific project webpage.
To look up your property’s assessment information, go to the Assessor’s Office Property Look-up website. Enter either the address or parcel number and then select Special Assessment from the menu on the left.
For questions about the assessment mailings and the general assessment process contact Engineering administrative staff at 608-266-4751 or ENAdmin@cityofmadison.com.

For questions about paying your assessment contact Danah Enright of the Finance Office at 608-266-4008 or DEnright@cityofmadison.com.