Serial numbers; possession of untraceable firearms; privately made firearms; serial number request system; requests for serial numbers; application of section; promulgation of rules and regulations
M.G.L. c. 140, § 121C
in effectc. 140, § 121C. Serial numbers; possession of untraceable firearms; privately made firearms; serial number request system; requests for serial numbers; application of section; promulgation of rules and regulations
Section 121C. (a) All firearms shall have a serial number in accordance with the requirements of this section. To meet serialization requirements all firearms shall be conspicuously engraved, cast or otherwise permanently embedded with a unique serial number on the frame or receiver; provided, that the serial number shall be placed in a manner not susceptible of being readily obliterated, altered or removed and shall be engraved, cast or otherwise permanently embedded to a depth of not less than.003 inches and in a print size not less than 1/16 inch; provided further, that the serialization of firearms, frames and receivers made from non-metallic materials shall be accomplished by using a metal plate permanently embedded in the material of the frame or receiver.
(b) No person shall knowingly possess, manufacture or assemble, cause to be manufactured or assembled, purchase, offer for sale, sell or otherwise transfer or import an untraceable firearm in the commonwealth; provided, however, that lawfully owned firearms imported or acquired by: (i) new residents moving into the commonwealth or acquired by heirs or devisees through distribution of an estate shall be serialized within 60 days of import or acquisition; and (ii) licensed firearms dealers, gunsmiths, distributors or manufacturers shall be serialized within 7 days of import or acquisition.
(c) No person shall manufacture or assemble a privately made firearm without: (i) obtaining a unique serial number from the department of criminal justice information services prior to manufacture or assembly; (ii) serializing the firearm with the obtained serial number during manufacture or assembly; and (iii) registering the firearm with the department of criminal justice information services in accordance with section 121B within 7 days of the firearm's manufacture or assembly.
(d) No person shall manufacture or assemble a privately made firearm that does not comply with all relevant state and federal safety regulations.
(e) The department of criminal justice information services shall develop and maintain a serial number request system to electronically receive, record and process requests for a unique serial number in accordance with this section. The serial number request system shall be integrated with the electronic firearms registration system maintained by the department of criminal justice information services pursuant to section 121B and shall be able to register all firearms and report firearm transactions pursuant to said section 121B and ensure that all data on privately made firearms is available for data collection pursuant to section 121E and tracing purposes pursuant to 131Q.
(f) Requests for a unique serial number through the serial number request system shall include information on the person requesting a unique serial number, whether the request is for a privately made firearm, the type of firearm to be serialized and, if privately made, the means and manner of its production.
(g) The requirements of this section shall not apply to firearms: (i) being delivered to law enforcement for the sole purpose of their destruction; (ii) possessed by common carriers and their duly authorized employees and agents while performing the regular and ordinary transport of firearms as merchandise for customers licensed to permit such transport; (iii) possessed by individuals lawfully traveling through the commonwealth in the care and custody of a nonresident owner provided that the firearms are stored in accordance with sections 131C and 131L; (iv) that are the property of the government of the United States; (v) produced by federally licensed manufacturers not for sale in the commonwealth; or (vi) manufactured prior to October 22, 1968.
(h) The executive office of public safety and security, in consultation with the department of criminal justice information services, shall promulgate rules and regulations for the implementation of this section, including technical requirements for the serialization of firearms, procedures for requesting serial numbers and procedures for public notice and an outreach campaign to promote awareness of this section.
Source: Massachusetts General Court (malegislature.gov)URL: https://malegislature.gov/Laws/GeneralLaws/PartI/TitleXX/Chapter140/Section121CFetched: 10/20/2026