Mass. Gen. Laws ch. 280 § 6A
Before imposing a fine or forfeiture as a punishment or part punishment for a crime, the court or justice shall levy as a special cost assessment an amount equal to twenty-five per cent of the fine or forfeiture; provided however, that no special cost assessment shall be levied on fines or forfeitures for minor motor vehicle offenses, and juvenile offenses or acts of delinquency. Minor motor vehicle offenses shall be defined as those not punishable by incarceration.
When a fine is suspended, in whole or in part, the special cost assessment shall be computed on the fine remaining to be paid. The court or justice may waive all or any part of said cost assessment upon a finding that such payment would cause a substantial financial hardship to the person, the person's immediate family or the person's dependents.
Said cost assessment shall be accounted for by the clerk of the court and forwarded to the state treasurer who shall deposit such assessment in the General Fund.
Mass. Gen. Laws ch. 280, § 6A