The State of California allows for seniors a one time property tax transfer but the Proposition is not honored in all Counties.
Here is some information from the CA state Board of Equalization’s website.
What are Propositions 60 and 90?
Propositions 60 and 90 are constitutional amendments passed by California voters that provides property tax relief for persons aged 55 and over. Implemented by section 69.5 of the Revenue and Taxation Code*, it allows these persons, under certain conditions, to transfer a property’s factored base year value from an existing residence to a replacement residence.
Typically the property tax of a newly purchased or constructed residence is based on its current market value upon change of ownership. However, the provisions of Propositions 60 and 90 may result in substantial tax savings since it allows the adjusted base year value of the original (sold) property to be transferred to the newly purchased or constructed home if eligibility requirements are met.
* Section 69.5 also sets forth the provisions of Proposition 110 which allows the transfer of a base year value for severely and permanently disabled persons. Except for the disability factor, the qualifications for Propositions 60/90 are same as Proposition 110.
For more information about how to transfer your taxes visit this link to the Board of Equalization.