Chapter 135 of the Acts of 2024: What Changed

Chapter 135 of the Acts of 2024^[1], titled "An Act Modernizing Firearm Laws," was signed by Governor Healey on July 25, 2024. The law took effect on October 2, 2024. The act has 160 sections and amends multiple chapters of the General Laws.

New Definitions

• Assault-style firearm: Replaces "assault weapon" with a broader definition that adds functional characteristics tests and a new "copy or duplicate" test based on internal components and receiver interchangeability, while retaining the existing named model list (AR-15, AK, UZI, and others)^[2]
• Untraceable firearm (ghost gun): A firearm that has not been serialized, or whose serial or other identification number has been removed, defaced, altered, obliterated or mutilated (Section 121). The statute uses "untraceable firearm" and "privately made firearm" as the defined terms.
• Covert firearm: A firearm placed in a camouflaging firearm container, or a firearm that is not a stun gun, is capable of discharging a bullet or shot and is constructed in a shape that does not resemble a firearm or is not immediately recognizable as one
• Machine gun (expanded): Now includes a firearm modified by automatic conversion, including through an automatic part such as a switch or auto sear. Bump stocks and trigger modifiers such as trigger cranks are defined separately and regulated under Chapter 269, Section 10
• Firearm (redefined): Now covers a weapon "designed to or may readily be converted to" expel a shot or bullet, while still excluding antique and permanently inoperable firearms

Restructured Assault Weapons Ban

The assault-weapons prohibition and its grandfather clause are both in Section 131M^[4]. Subsection (a) bans possessing, owning, selling, offering for sale, or transferring an assault-style firearm or large capacity feeding device, and the later subsections grandfather assault-style firearms lawfully possessed on August 1, 2024 and large capacity feeding devices lawfully possessed on September 13, 1994. Section 128^[3] is a separate provision setting penalties for unlicensed sales and dealer-licensing violations. Assault-style firearms lawfully possessed on August 1, 2024, by an LTC or dealer-license holder may be retained if registered and serialized.

FID Scope Narrowed

The Firearms Identification Card now entitles its holder to purchase, transfer, possess and carry rifles and shotguns that are not large capacity or semi-automatic, and a holder may use other firearms under the direct supervision of a License to Carry holder at an incorporated shooting club or a licensed shooting range. Possession of semiautomatic rifles and shotguns otherwise requires a License to Carry unless a Section 129C exemption applies.

Untraceable Firearm and 3D Printer Provisions

New Section 121C^[5] bans knowingly possessing, among other acts, an untraceable firearm (one that has not been serialized). Section 121D^[6] regulates 3D printers and CNC milling machines used to manufacture or assemble firearms.

Extreme Risk Protection Orders

Sections 131R through 131Y^[7], originally created by Chapter 123 of the Acts of 2018, were expanded by Chapter 135 to remove the requirement that the respondent hold an active firearms license and to broaden who may petition for an order to include medical professionals and school administrators.

Licensing Changes

• Replaced Section 131 with updated LTC rules (the practical elimination of Class B occurred under Chapter 284 of 2014)
• New live-fire training requirements,
• Firearm Licensing Review Board under Section 130B^[8] (created by Chapter 150 of 2004). Chapter 135 provides that not less than $50,000 of the license fee funds deposited into the General Fund be allocated to the board for its operations
• Transition from MIRCS to the Unified Gun Portal through MyMassGov

New Prohibited Areas

Chapter 135 added Section 10(k) to Chapter 269, making it unlawful to carry firearms in government administrative buildings, courthouses, correctional facilities, and polling places. Municipalities may opt out for their own administrative buildings.

Enhanced Storage Penalties

Section 131L keeps its tiered penalties, which rise sharply when a person under 18 may access an improperly stored firearm, up to a fine of $20,000 and imprisonment of 15 years for a large capacity firearm. Chapter 135 replaced weapon with firearm in the section and added semiautomatic firearms to the higher penalty tier, without otherwise rebuilding the tiers.

EOPSS Guidance

The Executive Office of Public Safety and Security has issued multiple guidance letters addressing implementation^[9], including Guidance Letters #1 through #4 covering administrative procedures, dealer obligations, and the transition timeline.

2026 Ballot Referendum

A veto referendum qualified for the November 3, 2026 ballot as Question 9 ("Firearms Regulation"). A YES vote would keep the law in effect. A NO vote would repeal Chapter 135.