Mass. Gen. Laws ch. 60 § 48
If at the time and place of sale no person bids for the land offered for sale an amount equal to the tax and charges, and if the sale has been adjourned one or more times, the collector shall then and there make public declaration of the fact; and, if no bid equal to the tax and charges is then made, he shall give public notice that he purchases for the town by which the tax is assessed said land as offered for sale at the amount of the tax and the charges and expenses of the levy and sale. Said amount, together with the cost of recording the deed of purchase, shall be allowed him in his settlement with such town, provided he has caused the deed to be duly recorded within sixty days after the purchase and to be delivered to the town treasurer.
Mass. Gen. Laws ch. 60, § 48