Mass. Gen. Laws ch. 106, § 9-408
(a) Term restricting assignment generally ineffective. Except as otherwise provided in subsection (b), a term in a promissory note or in an agreement between an account debtor and a debtor which relates to a health-care-insurance receivable or a general intangible, including a contract, permit, license, or franchise, and which term prohibits, restricts, or requires the consent of the person obligated on the promissory note or the account debtor to, the assignment or transfer of, or creation, attachment, or perfection of a security interest in, the promissory note, health-care-insurance receivable, or general intangible, is ineffective to the extent that the term:
(c) Legal restrictions on assignment generally ineffective. A rule of law, statute, or regulation that prohibits, restricts, or requires the consent of a government, governmental body or official, person obligated on a promissory note, or account debtor to the assignment or transfer of, or creation of a security interest in, a promissory note, health-care-insurance receivable, or general intangible, including a contract, permit, license, or franchise between an account debtor and a debtor, is ineffective to the extent that the rule of law, statute, or regulation:
(d) Limitation on ineffectiveness under subsections (a) and (c). To the extent that a term in a promissory note or in an agreement between an account debtor and a debtor which relates to a health-care-insurance receivable or general intangible or a rule of law, statute, or regulation described in subsection (c) would be effective under law other than this article but is ineffective under subsection (a) or (c), the creation, attachment, or perfection of a security interest in the promissory note, health-care-insurance receivable, or general intangible:
(f) Inapplicability. This section does not apply to an assignment or transfer of or creation of a security interest in: