For fiscal year 2018, the residential property tax rate in Somerville, MA is $11.32 per $1,000 of assessed value. This is a decrease of 35 cents or 2.8% from 2017. For fiscal year 2017, the Somerville residential exemption is $254,867. The full residential exemption reduces a Somerville homeowner's taxes by $2,885.09 in 2018. The residential exemption is for owners who reside in their Somerville property.