What is the difference between the RMV and the AV?

The RMV is the Assessor’s determination of the real market value of your property. The AV is the value used to calculate your taxes. Typically it is the 1995 RMV minus 10%, which became the 1997 Measure 50 (M50) assessed value. Each year this amount is subject to a 3% increase, plus any exception value that arises from changes to your property improvements.