State law requires the Assessor's Office to reappraise property immediately upon change in ownership or completion of new construction. The Assessor's Office must issue a supplemental assessment which reflects the difference between the prior assessed value and the new assessment. This value is prorated based on the number of months remaining in the fiscal year, ending June 30. If the reappraisable event occurs between January 1 and May 31, a supplemental assessment is made for both the current and the subsequent fiscal years. This is in addition to the regular tax bill. Notices of the supplemental assessments are mailed out to property owners prior to the issuance of the supplemental tax bill.