State legislation (SB 813) enacted in 1983 resulted in the Supplemental Property Tax affecting those who acquire property or complete new construction after July 1, 1983. The law requires that you receive a Supplemental Assessment Notice and tax bill covering the period from your acquisition of the property (or completion of new construction) to the end of the fiscal year or years affected.

If the change in ownership or completion of new construction occurred between January 1 and May 31, there will be two Supplemental Assessments, one in effect for the remainder of the fiscal year in which the assessable event took place and one in effect for the following fiscal year. If an assessable event occurs between June 1 and December 31, there will be only one Supplemental Assessment in effect for the remainder of that fiscal year. Supplemental Assessments reflect the difference between the new base year value and the previous value and/or values on the roll being prepared. These assessments will generate taxes in addition to the taxes based on the regular assessment roll. The notice you receive will advise you of both the Supplemental Assessment amount(s) and your Regular Assessment.

If the Supplemental Assessment represents a reduction in value, a tax refund may be in order. If so, the County Auditor shall make a refund of a prorated portion of taxes paid on assessments made on the current assessment roll or the roll being prepared. If you have not received your refund within three months of the date on which you received your negative supplemental notice, contact the County Auditor's Office at (530)225-5771.

New construction will be excluded from Supplemental Assessment if the owner notifies the Assessor in writing prior to, or within 30 days of, the commencement of construction, that he or she intends to offer that property for sale and does not intend to rent, use, lease, occupy or otherwise use that property. Exclusion forms are available in the Assessor's Office or download Claim for New Construction Exclusion From Supplemental Assessment.