Section 131M:
Grandfathering Assault-Style Firearms (Massachusetts)

Massachusetts General Laws Chapter 140, Section 131M^[1] contains both the primary prohibition on assault-style firearms and large capacity feeding devices under subsection (a), and the grandfathering framework for lawfully possessed pre-ban items under subsections (b) and (c). Chapter 135 restructured the former assault weapons ban so that the prohibition and grandfathering provisions are both housed in Section 131M, while Section 128 was amended in its first paragraph to cover dealers who sell or furnish a firearm or ammunition to a person without a firearm license, card, or permit.

Cutoff Dates

Section 131M establishes two statutory cutoff dates, each applying to a different category of restricted item:

• September 13, 1994: Applies to large capacity feeding devices. LCFDs lawfully possessed before this date are exempt from the prohibition under Section 131M(c), subject to location-based possession restrictions. This date corresponds to the original federal Assault Weapons Ban.
• August 1, 2024: Applies to assault-style firearms as defined by Chapter 135. Section 131M(b) exempts assault-style firearms "lawfully possessed within the commonwealth" on this date by a holder of a License to Carry under Section 131 or a dealer's license under Section 122, provided the firearm is registered under Section 121B and serialized under Section 121C. This is the primary new cutoff introduced by Chapter 135.

These dates are not interchangeable. Applying the wrong date to the wrong category of item is a common and potentially serious error.

Note: The July 20, 2016 date referenced in the broader assault weapons framework relates to the Attorney General's enforcement notice^[2] on copies and duplicates. That date does not appear in Section 131M itself. It does appear in the current Section 121 definition of assault-style firearm, where the copy-or-duplicate clause does not reach a firearm sold, owned, and registered before July 20, 2016.

Conditions for Grandfathering

To retain lawful possession of a grandfathered assault-style firearm under Chapter 135 of the Acts of 2024^[3], the owner must:

• Hold a valid License to Carry (LTC) or, as a dealer, a license to sell under Section 122
• Register the firearm through the Electronic Firearms Registration system under Section 121B
• Ensure the firearm bears a valid serial number under Section 121C
• Store the firearm in compliance with Section 131L

Location Restrictions for Grandfathered LCFDs

Section 131M(c) imposes specific location-based restrictions on the possession of large capacity feeding devices lawfully possessed before September 13, 1994. Unlike grandfathered assault-style firearms under Section 131M(b), which have no location restrictions beyond general law, grandfathered LCFDs may only be possessed in the following locations:

• On private property owned or controlled by the possessor
• On private property not open to the public, with the express permission of the property owner or the property owner's authorized agent
• At a licensed dealer or gunsmith, for the purpose of repair
• At a licensed firing range or sports shooting competition venue
• While traveling to and from these locations, provided the LCFD is stored unloaded and secured in a locked container in accordance with sections 131C and 131L

These location restrictions are distinct from the prohibited-areas provisions under Section 10(k) of Chapter 269, which apply to firearms generally. The Section 131M(c) restrictions apply specifically and exclusively to grandfathered LCFDs.

Transfer Restrictions

Warning: Grandfathered LCFDs are subject to strict transfer limitations. They may only be transferred to:

1. An heir or devisee (inheritance only)
2. A person residing outside the Commonwealth of Massachusetts
3. A licensed dealer

Outside the transfer and possession exemptions in Section 131M(e), no other transfers are permitted. Private sales of grandfathered LCFDs to other Massachusetts residents are prohibited outside those exemptions, even if both parties hold valid LTCs. Section 131M(b) provides that subsection (a), which bars owning, selling, or otherwise transferring an assault-style firearm, does not apply to a qualifying firearm lawfully possessed on August 1, 2024 by an LTC holder or a Section 122 licensee. Unlike Section 131M(c) for LCFDs, it states no list of permitted transferees and does not say whether a new in-state owner may receive the firearm. Transfer to a licensed Section 122 dealer, an heir or devisee, or an out-of-state resident is the conservative path, and owners should confirm any intended transfer with EOPSS before acting, because a first offense under Section 131M(d) is punishable by a fine of $1,000 to $10,000, imprisonment of 1 to 10 years, or both. Interstate transfers must comply with both Massachusetts and federal law.

2026 Ballot Referendum

The provisions of Section 131M, along with the rest of Chapter 135, are subject to a ballot referendum scheduled for November 3, 2026. If voters reject Chapter 135 with a No vote on Question 9, the Chapter 135 amendments to Section 131M and the broader assault weapons framework could be reversed, potentially restoring the prior statutory scheme. Firearms owners should monitor the referendum closely as the outcome will directly affect grandfathering eligibility and registration requirements.

See also: Three Grandfathering Dates and the Burden of Proof