Some can! If either spouse is over age 55, and they are buying a home of equal or lesser value than the home they are selling, and they are buying within the same county, then the old property tax can become the property tax for the new home. Many counties will allow buyers from others counties to bring their tax base with them, but not all counties will accept this reduced tax base – Riverside will not, Los Angeles will. But all counties will accept transfers within the county itself. These residential tax laws are known as Proposition 60 and 90.