You pay no property tax at all on the home you live in if you are the unremarried surviving spouse of a service member who died in a combat zone, died from an illness or injury received in a combat zone, or was declared missing in action and presumed dead.
Apply to the assessor in the Massachusetts city or town where the property is. You have to apply again every year.
The report of casualty or death certificate, documentation tying the death to combat zone service or a missing in action determination, your marriage certificate, proof you occupy the home as your domicile, and proof of your Massachusetts residency.