The State Department of Revenue (DOR) has approves assessed values each fiscal year for the Somerville Board of Assessors. The assessed values and data presented reflects information available for the FY 2014-2018 actual tax bills issued January 1 of each year. Assessments for each fiscal year have an effective market date of January 1 of the preceding year.

Note that ownership information shows record owner as of January 1. However, a second line of ownership, if applicable, showing "S/O" indicates a subsequent owner who purchased the property after January 1 but prior to the following assessment. In this instance, title information including sale price, sale date, and book & page will not appear in the data base until next year.