California Proposition 90 was an amendment of the Constitution of California relating to property tax assessments for older homeowners. It was proposed by the California State Legislature and approved by voters in a referendum held on November 8, 1988. The amendment allows homeowners over the age of 55 to transfer the assessed value of their present home to a replacement home if the replacement home is located in another county, is of equal or lesser value than the original property, if the county of the replacement dwelling adopts an ordinance participating in the program.