The Assessor is required under Massachusetts General laws: Chapter 59, to list and value all real and personal property. Valuation is subject to ad valorem taxation on an assessment roll each year. The "ad valorem" bases for taxation means that all property should be taxed "according to value" which is the definition. Assessed values in Massachusetts are based on full and fair cash value, or 100 percent of market value.
Assessors are required to submit these values to the Massachusetts Department of Revenue for certification every three years. In the years between certification the Assessors must also maintain values and make adjustments according to market conditions. The Town of Needham reassesses values each and every year. This is done so that the property taxpayer pays his or her fair share of the cost of local government in proportion to the amount of money the property is worth, on a yearly basis rather than every three years.
The Needham Assessors Office appraises and assesses approximately 12,000 parcels of real and personal property each year.