Mass. Gen. Laws ch. 142A § 14
The following persons are not required to be registered under this chapter: the commonwealth or any of its political subdivisions; any school, public or private, offering as part of a vocational education program courses and training in any aspects of home construction or home improvements; electricians, plumbers, architects or any other persons who are required by law to attain standards of competency or experience as a prerequisite to licensure for and engaging in such profession and who are acting exclusively within the scope of the profession for which they are currently licensed pursuant to such other law, construction supervisors excepted; persons dealing in the sale of goods or materials who neither arrange to perform nor perform directly or indirectly any work or labor in connection with the installation of or application of the goods or materials; persons building their own home or personally doing the renovations; any individual who performs labor or services for a contractor or subcontractor, for wages or salary and who does not act in the capacity of a contractor; any contractor or subcontractor who works on one undertaking or project by one or more contracts where the aggregate contract price is less than five hundred dollars; provided, however, that the contract is not in an amount of less than five hundred dollars for the purpose of evading this chapter; any person who engages in the business of a contractor or subcontractor on other than a full-time basis, and who has earned in gross revenues, as a contractor or subcontractor, less than five thousand dollars in the previous twelve-month period; any person acting as a contractor or subcontractor who was enrolled as a full-time student in a secondary school or college with degree granting authority from the government of the state in which the school is located, for the immediately preceding academic semester and is also enrolled as a full-time student for the next academic semester, in the same or a similar degree granting secondary school or college provided that at least two-thirds of the number of the employees of the contractor or subcontractor are similarly enrolled in secondary schools or colleges and that the contractor or subcontractor does not reasonably expect to earn or does not in fact earn, in gross revenues, more than five thousand dollars; persons who install central heating, air-conditioning systems, energy-conservation devices, or provide conservation services conducted by or on behalf of a public utility under a program approved by the department of public utilities; any contractor or subcontractor who works exclusively in any of the following home improvement areas: landscaping; interior painting or wall covering; or finished floor covering, including but not limited to carpeting, vinyl floor covering, tile; or fencing or freestanding masonry walls; or above-ground swimming pools; or shutter or awning installation; or ground level patios; or asphalt and driveway installation and maintenance.
Mass. Gen. Laws ch. 142A, § 14