Assessment Appeals Board

Board of Supervisors

The Assessment Appeals Board hears appeals from taxpayers on property assessments. This Board is governed by the rules and regulations of the Board of Equalization and Property Tax Laws of the State of California.

These are the general assessment appeal guidelines. Specific questions regarding the assessment appeal process should be directed to the Assessment Appeals clerk at (415) 473-7345, the Assessor's office (415) 473-7215 or by consulting other professionals in the field. You can also email the Assessment Appeals Board directly.

Due to the COVID-19 pandemic, in compliance with local and State shelter-at-home orders, Assessment Appeals Board hearings will be held via videoconference until further notice.  Members of the Assessment Appeals Board and staff will participate in hearings via videoconference.

Members of the public may observe Assessment Appeals Board hearings.  Approximately 30 minutes prior to the start of an Assessment Appeals Board hearing, the broadcast will be "live".  You can watch on Granicus.  (See the link below under "Upcoming Events".)


How to Appeal

Discuss Your Application with the Assessor's Office

You are urged to discuss the basis of your assessment with the Assessor's staff. If you do not agree as to the taxable value, you may file an "Assessment Appeal Application." You must file a separate Assessment Appeal Application form for each Assessor's Parcel or Property Identification number. You must also file a separate Assessment Appeal Application for each additional tax bill for the Assessor's Parcel or Property Identification number (regular assessment, supplemental assessment(s), roll change(s), escape assessment(s) or calamity reassessment).

After filing within the deadline you may still attempt to reach agreement with the Assessor anytime up to the date set for the Assessment Appeals Board hearing.

Complete an Application

The required form and instructions to appeal an assessment are available to print here: Assessment Appeal Application. You may print before or after filling out the form, which requires a blue ink signature before submitting.  You may also pick up a form at the Assessment Appeals Board office located at the Marin County Civic Center, 3501 Civic Center Drive, Room 329, San Rafael, California, or the form may be requested by contacting the Assessment Appeals Board office at (415) 473-7345. Please leave your name, mailing address and telephone number.

The State Board of Equalization has prepared a pamphlet to assist you in completing the Assessment Appeal Application. You may download a copy of Publication 30, Residential Property Assessment Appeals or contact the clerk of the Assessment Appeal Board office for a copy.  Publication 30 will also guide you through the entire Assessment Appeals process.  In preparing for your hearing, you must make value adjustments for differences between your property and that of each comparable sale presented.  To assist in that process, you may substitute the Marin County Residential Property Tax Comparison Work Sheet for the work sheet on page 16 of Publication 30.

In addition, the State Board of Equalization has a video online that explains the process of preparing and presenting your appeal at the Assessment Appeals Board.

Application Processing Fee

There is a $50 non-refundable processing fee for each Application. Payment can be made by check or money order payable to "County of Marin." We do not accept credit cards. Applications submitted without the processing fee will be returned unprocessed. Applicant will be charged an additional $30 fee by the County should their check be returned because of insufficient funds. Applicant will be required to pay the NSF bank fee.

Return Application by the Deadline

Assessment Appeal Applications for the regular assessment period must be filed between July 2 and November 30 of each year by 5:00 p.m. Assessment changes made outside of the regular assessment period; i.e., supplemental, roll change, escape, must be filed no later than 60 days after the date of mailing of the tax bill (California Revenue and Taxation Code, Section 1605 (c), and as adopted by the County Board of Supervisors, Resolution 91-204). Calamity Reassessment Appeals: If you disagree with the value stated on a reassessment notice sent to you because your property was damaged due to a natural disaster or other calamity, you must file within six (6)  months of the mailing of the notice. APPLICATIONS CANNOT BE ACCEPTED UNLESS FILED ON TIME.

An Assessment Appeal Application which does not state the Applicant's Opinion of Taxable Value (market value) is not valid and cannot be acted upon by the Assessment Appeals Board.

Filing an application for reduced assessment does not relieve the Applicant from the obligation to pay the taxes on the subject property on or before the applicable due date shown on the tax bill. If a reduction is granted, a proportionate refund of taxes paid will be made by the County Finance office.

Based on the evidence, the Assessment Appeals Board can increase as well as decrease an assessment. The decision of the Board upon the application is final; the Board may not reconsider or rehear any application. However, either the Applicant or the Assessor may bring timely action in superior court for review of an adverse decision.

Receiving Notice of Your Hearing Date

After filing an application you will receive a Notice of Hearing and a Hearing Date Confirmation by mail 45 days prior to the hearing. You MUST complete and return the Hearing Date Confirmation Notice by fax, U.S. mail, email or in person at least 21 days before your scheduled hearing.

The Applicant and/or the Assessor's one-time request for postponement must be made not later than 21 days before the hearing is scheduled to commence (Property Tax Rule 323).

Hearings are open to the public. Feel free to attend hearings of other cases so that you may familiarize yourself with the procedures. You will be given a full opportunity to present your case and to challenge the Assessor's case. The Board will make every effort to see that all relevant evidence is considered.

Hearings are not reported by a stenographic reporter. However, the Applicant at his or her expense may arrange to have the hearing reported by a stenographer.

All hearings for the Assessment Appeals Board are audio recorded. An Applicant may at his or her expense request a copy or a transcript of the audio recording of the proceedings. Any such request must be made no later than sixty (60) days following the final decision by the Board.

If You Fail to Appear for Your Scheduled Hearing

If you fail to appear at a scheduled hearing, your application will be denied for lack of an appearance and you may refile an appeal during the next regular filing period in accordance with Revenue and Taxation Code Section 80.



Based on guidance from the California Department of Public Health and the California Governor’s Office, in order to minimize the spread of the COVID-19 virus, the Marin County Assessment Appeals Boards will be holding all hearings via video conferencing and the hearings will be accessible telephonically or otherwise electronically to the members of the public if public participation is requested. 

The video conferencing hearings may be joined by counsel and other participants by use of the desktop/laptop application (or alternate teleconferencing platform), a web browser for those without the application or alternate platform, or a smart device (such as iOS or Android smart phones or tablets). The desktop/laptop application provides the most functionality and flexibility.

Applicants who do not have access to a computer or smart device, and who have no access to the remote proceeding, may seek advance authorization to appear personally at the hearing with the clerk.  Please note that the Assessment Appeals Board members will be appearing remotely. Please refer to the Zoom meeting instructions for information on how to join the online meeting.


The Board requests that the Assessor and Applicant submit exhibits to the Assessment Appeals Board clerk as follows:

Hard copy exhibits are due seven days in advance of your AAB hearing; electronic copies (which can be attached below) are due three days in advance.

The three elements described below should be included on the lower-right hand corner of the hard copy exhibit(s) you submit.

  1. Application Number — example: 18-1234.
  2. Party submitting exhibit(s) — example: Applicant.
  3. The exhibit number — example: Ex1.

In this example the result would be: 18-1234-Applicant-Ex1.

For electronic exhibit files submitted, the three elements described below should be used for the naming of your electronic exhibit file(s).

  1. Application Number — example: 18-1234.
  2. Party submitting exhibit(s) — example: Applicant.
  3. The exhibit number — example: Ex1.

In this example the result would be: 18-1234-Applicant-Ex1.pdf.

An online form is available to facilitate electronic submission of exhibits.

PDF documents are preferred in order to protect document integrity, but other file types allowed include doc, docx, xls, xlsx, txt, jpg, jpeg, png, gif. Please check to make sure hard copy documents/photographs are scanned clearly.

The exhibits will be securely distributed to Board members.  Board members will not review exhibits prior to the hearing.  This does not preclude the Assessor or Applicant from providing further exhibits or evidence at the hearing.

Hearing Rules

When joining a videoconference hearing, please keep in mind the following rules of virtual hearing etiquette:

  • Be on time. You must join the videoconference and connect to the hearing at least 30 minutes prior to your scheduled hearing. 
  • Stay on the videoconference line, even if there is only silence, until the hearing begins. Listen quietly until your application is called.
  • When your application is called, speak one at a time and pause prior to speaking in case there is any video/audio lag. The Assessment Appeals Board must ensure that the statements of participants are audible to all other participants and staff and that the statements made by a participant are identified as being made by that participant.
  • Parties will have an opportunity to speak, so please be patient.
  • Please mute your electronic device when you are not speaking.
  • If you need to speak, please raise your hand (when appearing on video).
  • Parties must appear in a quiet, private area with minimal background noise. Whenever speaking, first identify yourself.


In order to prevent delay, to the extent a witness will be called at any hearing, parties should identify the witness(s) seven calendar days prior to the hearing, by using this data submission form (as noted above). If you have a witness appearing on your behalf, you are responsible for providing the witness with the Zoom participation information. This does not preclude the Assessor or applicant from calling other witnesses at the hearing.


If you are seeking Findings, the Board requests that you provide a check for the required deposit to the clerk at 3501 Civic Center Drive, Room 329, San Rafael, CA 94903 no later than 7 calendar days prior to your hearing.  If Findings are requested at the hearing and you have not submitted a deposit to the clerk, the clerk will provide a date certain to provide the deposit. If the deposit for the Findings is not received by that date, the Board will issue its decision without Findings.


Instructions to join the Zoom meeting for your Assessment Appeals Hearing:

Click the following link:

Join by computer or mobile device Join by telephone
Visit Dial: (669) 900-6833
Meeting ID: 912 9247 5042 Meeting ID: 912 9247 5042 #
Password: 940376 Password: 940376 #
Use the "Raise Hand" button to inform the moderator that you would like to comment. Press *9 to inform the moderator that you would like to comment.

If you have questions or difficulty, please contact the Assessment Appeals Board Clerk at (415) 473-7345.