Mass. Gen. Laws ch. 109, § 25

A general partner of a limited partnership may make contributions to the partnership and share in the profits and losses of, and in distributions from, the limited partnership as a general partner. A general partner also may make contributions to and share in profits, losses, and distributions as a limited partner. A person who is both a general partner and a limited partner has the rights and powers, and is subject to the restrictions and liabilities, of a general partner and, except as provided in the partnership agreement, also has the powers, and is subject to the restrictions, of a limited partner to the extent of his participation in the partnership as a limited partner.