Property owners need to be vigilant about their property value when the new assessments come out on May 1 in Colorado. Since the 2009 reevaluation, trends point to a decline in real estate value for the 2011 reassessment. A decline in property value will not necessarily be commensurate with a decline in property tax. In fact, it is possible that property values will go down while taxes continue to rise. Property owners should exercise their appeal rights if appropriate.