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. Governor Healey signed an emergency preamble on October 2, 2024, making most provisions effective immediately. The law amends more than 150 sections across 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): Any firearm without a valid serial number, including those assembled from parts kits or 3D-printed components. The statute uses "untraceable firearm" and "privately made firearm" as the defined terms.
• Covert firearm: A firearm designed or modified to not be readily recognizable as a firearm
• Machine gun (expanded): Now includes bump stocks, trigger cranks, Glock switches, and auto sears
• Firearm (redefined): Now includes items "designed to or may readily be converted to" expel a projectile, eliminating the operability requirement for prosecution

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 firearms lawfully possessed before the effective date. Section 128^[3] is a separate provision setting penalties for unlicensed sales and dealer-licensing violations. Assault-style firearms lawfully possessed before August 1, 2024 may be retained if registered and serialized.

FID Scope Narrowed

The Firearms Identification Card now covers only non-large-capacity, non-semiautomatic rifles and shotguns. All semiautomatic rifles and shotguns now require a License to Carry.

Untraceable Firearm and 3D Printer Provisions

New Sections 121C^[5] and 121D^[6] ban the possession of unserialized firearms and regulate 3D printers and CNC machines used to manufacture firearm components.

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

• Removed remaining Class A / Class B language from the statutes (the practical elimination of Class B occurred under Chapter 284 of 2014)
• New live-fire training requirement (statutory effective date: April 2, 2026 (regulations still being finalized as of March 2026))
• Firearm Licensing Review Board amended under Section 130B^[8] (originally created by Chapter 150 of 2004, amended by Chapter 284 of 2014)
• 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 penalties were restructured into a tiered system with significantly higher penalties when minors may access improperly stored firearms, particularly large capacity weapons (fines up to $20,000 and imprisonment up to 15 years).

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 with 78,707 valid signatures. A YES vote would keep the law in effect. A NO vote would repeal Chapter 135. If repealed, the prior versions of all amended statutes would be restored.