What We Do
Assessor parcel maps
We create and update parcel maps for about 96,000 properties across Marin County. These maps help us assess property values fairly and accurately.
Our Mapping team updates maps when:
- New subdivisions or surveys are recorded
- Property lines change, like lot line adjustments
- Property owners request approved parcel combinations
- Other official documents or maps are recorded
These maps are for assessment purposes only.
We cannot provide legal or survey advice
By California law, our staff cannot give legal advice. This includes advice about:
- Which forms to use or how to fill them out
- Land surveys or survey results
- Legal descriptions or their accuracy
- Fence lines or parcel boundaries
- Easements or their locations on parcel maps
If you need help with any of these, please contact a licensed professional.
Mapping Services
- Search Assessor maps This information has been scanned by the Mapping Division of the Marin County Assessor's Department.
- How to Read an Assessor Parcel Map Helpful information for viewing and reading Marin County Assessor Parcel Maps.
- Assessor Parcel Map Maintenance & Parcel Number Creation Information regarding the maintenance and creation of new Marin County Assessor Parcel Maps.
- Assessor Parcel Combination Information about the combination of Marin County Parcels.
Information for residents
A copy of the legal description for your property can be found on the deed that was recorded when you purchased your property.
If you do not have a copy of your deed, you can get a copy at the Marin County Recorder's Office located at the Marin Civic Center Room 232, 3501 Civic Center Drive, San Rafael, CA. Office hours are from 9:00 AM to 4:00 PM excluding major holidays or you could order a copy online via the Recorder's Index:
Each Assessor Parcel Number (APN) is assigned to a certain Tax Rate Area (TRA) which is identified by a six-digit number. The TRA code assigned to your parcel appears on your tax bill. The first three (3) digits is the primary code. Each primary code number is for a specific jurisdiction. If the first three digits are 011 or lower, your property is located within an incorporated town or city. If the first three digits are greater than 011, then your property is located within the unincorporated area of Marin County.
Please note that the United States Post Office may designate or associate your property with a particular city; however, the property is only within the town/city boundary if the Tax Rate Area (TRA) identifies it as being in the town or city.
If you cannot find your TRA, you can call the Marin County Assessor at (415) 473-7215 or by email to get that information.
The Marin County Assessor is constantly updating and improving the Assessor Parcel Maps. Sometimes it is necessary to administratively change your Assessor Parcel Number (APN) due to our Assessor Parcel Map page layout and computer system limitations. Other reasons for changes to Assessor Parcel Map pages are land divisions, lot line adjustments, mergers, parcel combination, and tax rate area (TRA) changes.
A parcel number change done because of a recorded map or recorded deed between January 1 and December 31 of any given year is effective for the following Roll year. For example, a document filed November 15, 2024 will be effective for the 2025 Roll property tax bill that will be mailed in October 2025.