Mass. Gen. Laws ch. 140, sec. 131M — MA Code / Part I / Title XX / Chapter 140 / Section 131M
Assault weapon or large capacity feeding device not lawfully possessed on August 1, 2024; sale, transfer or possession; punishment; exceptions
Status: in_force

Section 131M. (a) No person shall possess, own, offer for sale, sell or otherwise transfer in the commonwealth or import into the commonwealth an assault-style firearm, or a large capacity feeding device. (b) Subsection (a) shall not apply to an assault-style firearm lawfully possessed within the commonwealth on August 1, 2024, by an owner in possession of a license to carry issued under section 131 or by a holder of a license to sell under section 122; provided, that the assault-style firearm shall be registered in accordance with section 121B and serialized in accordance with section 121C. (c) Subsection (a) shall not apply to large capacity feeding devices lawfully possessed on September 13, 1994 only if such possession is: (i) on private property owned or legally controlled by the person in possession of the large capacity feeding device; (ii) on private property that is not open to the public with the express permission of the property owner or the property owner's authorized agent; (iii) while on the premises of a licensed firearms dealer or gunsmith for the purpose of lawful repair; (iv) at a licensed firing range or sports shooting competition venue; or (v) while traveling to and from these locations; provided, that the large capacity feeding device is stored unloaded and secured in a locked container in accordance with sections 131C and 131L. A person authorized under this subsection to possess a large capacity feeding device may only transfer the device to an heir or devisee, a person residing outside the commonwealth, or a licensed dealer. (d) Whoever violates this section shall be punished, for a first offense, by a fine of not less than $1,000 nor more than $10,000 or by imprisonment for not less than 1 year nor more than 10 years, or by both such fine and imprisonment, and for a second offense, by a fine of not less than $5,000 nor more than $15,000 or by imprisonment for not less than 5 years nor more than 15 years, or by both such fine and imprisonment. [ Subsection (e) effective until August 5, 2025. For text effective August 5, 2025, see below.] (e) This section shall not apply to transfer or possession by: (i) a qualified law enforcement officer or a qualified retired law enforcement officer, as defined in the Law Enforcement Officers Safety Act of 2004, 18 U.S.C. sections 926B and 926C, respectively, as amended; (ii) a federal, state or local law enforcement agency; or (iii) a federally licensed manufacturer solely for sale or transfer in another state or for export. [ Subsection (e) as amended by 2025, 14, Sec. 45 effective August 5, 2025. For text effective until August 5, 2025, see above.] (e) This section shall not apply to transfer or possession by: (i) a qualified law enforcement officer or a qualified retired law enforcement officer, as defined in the Law Enforcement Officers Safety Act of 2004, 18 U.S.C. sections 926B and 926C, respectively, as amended; (ii) a law enforcement officer as defined in section 1 of chapter 6E who is currently certified pursuant to section 4 of said chapter 6E; provided, however, that to qualify for the exemption under this subsection, the certification of a law enforcement officer as defined in section 1 of chapter 6E shall not be suspended, limited, or restricted and the officer shall be permitted to perform police duties and functions involving firearms in accordance with chapter 6E and the regulations promulgated thereunder; (iii) a federal, state or local law enforcement agency; or (iv) a federally licensed manufacturer solely for sale or transfer in another state or for export.

Section 131M. (a) No person shall possess, own, offer for sale, sell or otherwise transfer in the commonwealth or import into the commonwealth an assault-style firearm, or a large capacity feeding device.

(b) Subsection (a) shall not apply to an assault-style firearm lawfully possessed within the commonwealth on August 1, 2024, by an owner in possession of a license to carry issued under section 131 or by a holder of a license to sell under section 122; provided, that the assault-style firearm shall be registered in accordance with section 121B and serialized in accordance with section 121C.

(c) Subsection (a) shall not apply to large capacity feeding devices lawfully possessed on September 13, 1994 only if such possession is: (i) on private property owned or legally controlled by the person in possession of the large capacity feeding device; (ii) on private property that is not open to the public with the express permission of the property owner or the property owner's authorized agent; (iii) while on the premises of a licensed firearms dealer or gunsmith for the purpose of lawful repair; (iv) at a licensed firing range or sports shooting competition venue; or (v) while traveling to and from these locations; provided, that the large capacity feeding device is stored unloaded and secured in a locked container in accordance with sections 131C and 131L. A person authorized under this subsection to possess a large capacity feeding device may only transfer the device to an heir or devisee, a person residing outside the commonwealth, or a licensed dealer.

(d) Whoever violates this section shall be punished, for a first offense, by a fine of not less than $1,000 nor more than $10,000 or by imprisonment for not less than 1 year nor more than 10 years, or by both such fine and imprisonment, and for a second offense, by a fine of not less than $5,000 nor more than $15,000 or by imprisonment for not less than 5 years nor more than 15 years, or by both such fine and imprisonment.

[ Subsection (e) effective until August 5, 2025. For text effective August 5, 2025, see below.]

(e) This section shall not apply to transfer or possession by: (i) a qualified law enforcement officer or a qualified retired law enforcement officer, as defined in the Law Enforcement Officers Safety Act of 2004, 18 U.S.C. sections 926B and 926C, respectively, as amended; (ii) a federal, state or local law enforcement agency; or (iii) a federally licensed manufacturer solely for sale or transfer in another state or for export.

[ Subsection (e) as amended by 2025, 14, Sec. 45 effective August 5, 2025. For text effective until August 5, 2025, see above.]

(e) This section shall not apply to transfer or possession by: (i) a qualified law enforcement officer or a qualified retired law enforcement officer, as defined in the Law Enforcement Officers Safety Act of 2004, 18 U.S.C. sections 926B and 926C, respectively, as amended; (ii) a law enforcement officer as defined in section 1 of chapter 6E who is currently certified pursuant to section 4 of said chapter 6E; provided, however, that to qualify for the exemption under this subsection, the certification of a law enforcement officer as defined in section 1 of chapter 6E shall not be suspended, limited, or restricted and the officer shall be permitted to perform police duties and functions involving firearms in accordance with chapter 6E and the regulations promulgated thereunder; (iii) a federal, state or local law enforcement agency; or (iv) a federally licensed manufacturer solely for sale or transfer in another state or for export.