Massachusetts Chapter 135:
Complete Guide to the New Gun Laws

Chapter 135 of the Acts of 2024^[1] is the most significant restructuring of Massachusetts firearms law since the Gun Control Act of 1998. Officially titled "An Act Modernizing Firearms Laws," it amended more than 150 sections of the General Laws across multiple chapters. Governor Healey signed the bill on July 25, 2024. She added an emergency preamble on October 2, 2024, making most provisions effective immediately. A second wave of provisions, primarily the revised training curriculum, took effect on April 2, 2026.

Key Dates

• October 2, 2024: Most provisions took effect (definitions, prohibitions, penalties, serialization requirements, ERPO expansion)
• October 2025: MIRCS Unified Gun Portal launched for registration and licensing
• April 2, 2026: Revised Basic Firearms Safety Course curriculum took effect (new applicants and renewals must complete updated courses)
• October 28, 2026: Deadline to register all firearms through the Unified Gun Portal (administrative compliance date set by EOPSS Guidance Letter #4)^[2]
• November 3, 2026: Ballot question -- voters decide whether to keep or repeal Chapter 135^[3]

What Changed: The Major Provisions

1. New Definitions

Section 121 was expanded with several new defined terms^[4]:

• Assault-style firearm: Replaces the former "assault weapon" terminology. Defined by both functional characteristics (clauses a through c) and a retained named model list (clause e), broadening the scope.
• Untraceable firearm (ghost gun): Any firearm, frame, or receiver lacking a serial number assigned by a licensed manufacturer, or with an altered/removed serial number.
• Covert firearm: A firearm designed or modified to not be readily recognizable as a firearm.
• 3D printer: Defined for the purpose of regulating manufacture of firearm components.
• Unfinished frame or receiver: Forgings, castings, or printed bodies intended to become functional receivers.

2. Universal Registration

Section 121B^[5] created a statutory basis for a statewide electronic firearms registration system. All firearms, including frames and receivers, must be registered through the MIRCS Unified Gun Portal by October 28, 2026. New residents have 60 days. Dealers and gunsmiths have 7 days of acquisition. Loss or theft must be reported within 7 days.

3. Serialization Requirements

Section 121C^[6] requires all firearms to bear a valid serial number. Owners of previously lawful unserialized firearms must apply for a serial number through DCJIS. Section 121D regulates 3D printers and CNC machines used to manufacture firearm components.

4. FID Scope Narrowed

The Firearm Identification Card now covers only non-large-capacity, non-semiautomatic rifles and shotguns. All semiautomatic rifles and shotguns, regardless of magazine capacity, now require a License to Carry (LTC). FID holders who possess semiautomatic firearms should apply for an LTC to remain in compliance.

5. Revised Safety Training (Effective April 2, 2026)

Chapter 135 mandated a revised Basic Firearms Safety Course curriculum including instruction on disengagement tactics, suicide prevention, safe storage, and a live-fire training component^[7]. The Massachusetts State Police published the list of approved courses on April 1, 2026. The live-fire component is not currently being enforced while EOPSS finalizes the implementing regulations. Persons who held an FID or LTC on or before August 1, 2024 are exempt from the live-fire requirement, including for renewals^[2].

BFS Portal Gap (April 2-14, 2026): The new instructor portal for issuing updated BFS certificates does not go live until April 14, 2026. During this two-week gap, instructors teaching the new curriculum cannot issue certificates. Students must create accounts on the new portal to print certificates. Pre-April 2 certificates remain valid indefinitely. EOPSS also requires a supplemental online training component (disengagement, suicide prevention, use of force) that must be completed in addition to the classroom/range course.

6. Prohibited Areas

New Section 10(k) of Chapter 269 creates "prohibited areas" where carrying a firearm is restricted: government administrative buildings, judicial and court buildings, correctional facilities, and ballot-storage, tabulation, polling, and early voting locations. Schools are addressed separately under Section 10(j), and healthcare facilities are not prohibited areas under Section 10(k). It is a defense if a licensed person securely stored the firearm in a vehicle while within the prohibited area.

7. Enhanced Penalties

Chapter 135 introduced tiered penalty structures for storage violations, new mandatory minimums for untraceable firearm possession (12-month minimum), and enhanced penalties for carrying in prohibited areas. Machine gun and bump stock provisions were expanded under Section 10(c) of Chapter 269.

8. Assault-Style Firearms Ban Update

Section 128 now prohibits assault-style firearms (new terminology), untraceable firearms, and covert firearms. Section 131M preserves grandfathering for assault-style firearms lawfully possessed before August 1, 2024 (and copies/duplicates of models identified under the July 20, 2016 AG enforcement notice). Large capacity feeding devices are grandfathered if manufactured before September 13, 1994. Active constitutional challenges include Capen v. Campbell (First Circuit) and Hanlon v. Campbell (D. Mass., NRA-backed).

9. ERPO Expansion

Sections 131R through 131Y expanded the Extreme Risk Protection Order framework, adding provisions for court-ordered firearm removal with enhanced procedural requirements.

What You Need to Do

1. Register all firearms through the MIRCS Unified Gun Portal before October 28, 2026
2. Check your license scope: If you hold an FID and own semiautomatic rifles or shotguns, apply for an LTC
3. Complete the revised safety course if you are a new applicant or renewing after April 2, 2026 (existing holders with licenses issued before August 1, 2024 are exempt from the live-fire component)
4. Review storage requirements: Penalties are now tiered and substantially harsher under Chapter 135
5. Know the prohibited areas: Carrying in government buildings, courthouses, schools, and other designated locations carries new criminal penalties

November 2026 Ballot Question

Chapter 135 is subject to a veto referendum on the November 3, 2026 ballot^[3]. The Civil Rights Coalition gathered over 100,000 signatures to place the question before voters. A YES vote keeps the law as enacted. A NO vote repeals Chapter 135 in its entirety. If repealed, Massachusetts firearms law would revert to the pre-October 2024 framework. Gun owners should comply with the current law regardless of the pending ballot question, as the law remains in full effect until and unless voters repeal it.

Ballot Wording Controversy: Gun Owners' Action League (GOAL) has accused AG Campbell of manipulating the ballot question wording so that a "YES" vote keeps the law and a "NO" vote repeals it, arguing this is counterintuitive for a repeal referendum. GOAL alleges the AG's office consulted with gun control organizations in drafting the language.

Court Challenges

Multiple federal court challenges are active:

• Capen v. Campbell (First Circuit, 2025): Challenges the assault-style firearms ban. The First Circuit affirmed the denial of a preliminary injunction in April 2025, applying the Bruen historical tradition framework. Do not cite Supreme Court docket No. 25-566 for Capen; docket No. 25-566 is Grant v. Higgins, a Connecticut case. Capen has returned to the District Court for further proceedings.^[9]
• Hanlon v. Campbell (D. Mass., filed August 2025): NRA-backed challenge to the assault-style firearms definition under the Second and Fifth Amendments. The Commonwealth filed its initial response in October 2025, asserting sovereign immunity. Pending.
• Commonwealth v. Thomson (SJC, argued March 2, 2026): Challenges the constitutionality of the age-21 LTC requirement under the Bruen framework. Under advisement.
• Granata v. Campbell (First Circuit): Challenges the Massachusetts Approved Handgun Roster and AG handgun sales regulations. The Trump DOJ filed an amicus brief in January 2026 supporting the challengers. Pending.