These two constitutional amendments, passed by California voters provide property tax relief for persons aged 55 and over. Implemented by section 69.5 of the Revenue and Taxation Code, they allow these persons, under certain conditions, to transfer a property’s factored base year value from an existing residence to a replacement residence.
Important to note about these two tax transfer initiatives is that Proposition 60 allows transfers of base year values within the same county (intracounty), while Proposition 90 allows transfers from one county to another county in California (intercounty) and it is the discretion of each county to authorize such transfers.
In the link below please find a WRT marketing piece on these propositions. For more technical answers to your questions, here’s the FAQ’s link as found on the California State Board of Equalization website: PROP 60/90