Massachusetts Constitution Amendments Art. LXIII, § 5

The governor may disapprove or reduce items or parts of items in any bill appropriating money. So much of such bill as he approves shall upon his signing the same become law. As to each item disapproved or reduced, he shall transmit to the house in which the bill originated his reason for such disapproval or reduction, and the procedure shall then be the same as in the case of a bill disapproved as a whole. In case he shall fail so to transmit his reasons for such disapproval or reduction within ten days after the bill shall have been presented to him, such items shall have the force of law unless the general court by adjournment shall prevent such transmission, in which case they shall not be law.