As we have written on extensively, Proposition 19, new for 2021 (replacing older propositions 58, 193, 60 and 90), has two main components, portability and inheritance. (Review our many articles on Prop 19 starting here, link to main prop 19 page.)
These two aspects can be combined in some regards, and not combined in others.
For example, if you inherit a property and qualify for Prop 19, and therefore keep that property’s low (prop 13) tax basis, you CAN then sell that property when you are 55 or older and transfer that same low (prop 13) tax basis to a new property. More details below.