Massachusetts Chapter 135:
Complete Guide to the New Gun Laws

Officially titled "An Act Modernizing Firearm Laws," Chapter 135 of the Acts of 2024^[1] contains 160 sections and amends provisions across several chapters of the General Laws. Governor Healey signed the bill on July 25, 2024. EOPSS guidance states that the law took effect on October 2, 2024. 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, ERPO expansion). Individuals must comply with the registration and serialization requirements from October 28, 2026
• April 2, 2026: Revised Basic Firearms Safety Course curriculum took effect for applicants subject to Section 131P. Persons lawfully holding an FID or LTC on August 1, 2024 are exempt from the course requirement when renewing.
• October 28, 2026: Registration requirements begin for firearms subject to Section 121B through the Unified Gun Portal (compliance date stated in EOPSS Guidance #5 under Section 157 of Chapter 135)
• November 3, 2026: 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 functional characteristics in clauses (a) through (c), roster listings in clause (d), and a retained named model list in clause (e), including specified copies or duplicates under clause (f). The exclusions in clause (g) apply.
• 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).
• Covert firearm: A firearm placed in a camouflaging firearm container, or a firearm other than a stun gun that 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.
• Unfinished frame or receiver: A forging, casting, printing, extrusion, machined body or similar item that may readily be completed or assembled to function as a frame or receiver, or is marketed or sold to the public for use as one once completed or assembled. Components designed and intended for use in an antique firearm are excluded.

2. Universal Registration

Section 121B^[5] created a statutory basis for a statewide electronic firearms registration system. Registration requirements for firearms subject to Section 121B, including frames and receivers, begin on October 28, 2026 through the MIRCS Unified Gun Portal. Firearms already registered through the transaction portal do not have to be registered again when the new system goes live. A new resident has 60 days to register firearms imported into the Commonwealth. Licensed dealers, gunsmiths, distributors and manufacturers have 7 days to register firearms they import. Other registrations are completed at the time of import, purchase, acquisition, manufacture or assembly, except that an heir or devisee has 60 days and a privately made firearm must be registered within 7 days. Loss or theft must be reported within 7 days, and a licensed dealer must report a loss or theft from the dealer's premises immediately.

3. Serialization Requirements

Section 121C^[6] establishes serialization rules and includes express exemptions, including qualifying pre-1968 firearms. A person manufacturing or assembling a privately made firearm must obtain the required serial number before manufacture or assembly. Section 121D separately regulates certain use and sale of 3D printers and CNC machines for firearm manufacture.

4. FID Scope Narrowed

The Firearm Identification Card ordinarily covers non-large-capacity, non-semiautomatic rifles and shotguns. Semiautomatic rifles and shotguns, regardless of magazine capacity, require a License to Carry (LTC), except under the direct supervision of an LTC holder at an incorporated shooting club or licensed shooting range, under Section 129C exemptions, or under the Section 153 transition rule. Section 153 of the Act lets a current FID holder keep possessing the firearms the card authorized until it expires or is suspended or revoked. 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^[2]. The Massachusetts State Police has approved courses that satisfy the academic requirements of the new law, and its list of approved courses was last updated on June 5, 2026^[7]. Under an EOPSS memorandum of March 26, 2026, live fire does not need to be included in a Basic Firearms Safety course until regulations are promulgated and live fire is fully implemented. Persons who lawfully held an FID or LTC on August 1, 2024 are exempt from Section 131P when renewing. Persons who possessed an FID or LTC before live firearms training is implemented are also exempt from that training requirement^[2].

6. Prohibited Areas

New Section 10(k) of Chapter 269 restricts firearm possession in government-controlled places used for administration, judicial or court administrative proceedings, or correctional services, including their buildings, grounds and parking areas. State-owned public hunting land is excluded, and a municipality may vote to exclude its administrative buildings. The restriction also covers ballot-storage or tabulation locations during voting or tabulation, polling places and early voting sites while open for voting, and areas within 150 feet of their building entrance doors. Schools are addressed separately under Section 10(j). Section 10(k) does not designate healthcare facilities as a separate category, but a facility may qualify if it meets the government-control and use requirements. It is a defense if a person with the necessary license or card securely stored the firearm in a vehicle within the prohibited area in accordance with Sections 131C and 131L of Chapter 140.

7. Enhanced Penalties

Chapter 135 kept the tiered penalty structure for storage violations that St. 2014, c. 284 created, extended its higher tier to semiautomatic firearms, and introduced a 12-month minimum term under Chapter 269, Section 11C for specified knowing manufacture, assembly, import, sale, transfer, purchase, or receipt of an untraceable firearm. Possession or control is prima facie evidence of the covered conduct, but bare possession is not listed as the sentenced offense. Machine-gun and bump-stock provisions were expanded under Section 10(c) of Chapter 269.

8. Assault-Style Firearms Ban Update

Section 131M contains the assault-style-firearm and large-capacity-feeding-device prohibition and its grandfathering conditions. Section 121C addresses untraceable firearms, while other Chapter 135 provisions address covert firearms. The consolidated Capen and Hanlon district-court proceeding has been stayed since July 9, 2026, when the court granted a joint motion to stay.

9. ERPO Expansion

Chapter 135 expanded the Extreme Risk Protection Order framework in Sections 131R through 131Y, adding provisions for court-ordered firearm removal with enhanced procedural requirements.

What You Need to Do

1. Register firearms subject to Section 121B through the MIRCS Unified Gun Portal beginning October 28, 2026
2. Check your license scope. If you hold an FID and own semiautomatic rifles or shotguns, apply for an LTC unless your existing FID still authorizes possession under Section 153 or another statutory exemption applies
3. Complete the revised safety course if you are a new applicant on or after April 2, 2026, subject to the exemptions in Section 131P. Persons lawfully holding an FID or LTC on August 1, 2024 are exempt from the course at renewal. Persons holding an FID or LTC before live-fire training is implemented are exempt from that component. EOPSS Guidance #5 requires a supplemental online course at renewal for persons issued an FID or LTC after August 1, 2024 but before October 2, 2024 whose applications were submitted after August 1, 2024
4. Review storage requirements: The Section 131L penalty tiers predate Chapter 135, which extended the higher tier to semiautomatic firearms
5. Know the prohibited areas. Section 10(k) creates penalties for possessing a firearm in designated government and election locations when the person knows or reasonably should know the location is prohibited, subject to its exceptions and vehicle-storage defense. Schools are governed separately by Section 10(j)

November 2026 Ballot Question

Chapter 135 is subject to a veto referendum on the November 3, 2026 ballot as Question 9 ("Firearms Regulation")^[3]. A YES vote keeps the law as enacted. A NO vote would repeal Chapter 135 in its entirety 30 days after the election, unless the law is approved by a majority of the voters voting on it or the NO votes are fewer than 30 percent of all ballots cast at that state election^[10]. If repealed, Massachusetts firearms law would revert to the pre-October 2024 framework. Gun owners should comply with the provisions currently in effect regardless of the pending ballot question.

Court Challenges

Court challenges to the law include:

• 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. Supreme Court docket No. 25-566 is Grant v. Higgins, a Connecticut case, rather than Capen. In the District Court, Capen was consolidated with Hanlon on October 20, 2025, and the consolidated case has been stayed since July 9, 2026.^[9]
• Hanlon v. Campbell (D. Mass., filed August 2025): Challenge by the National Rifle Association and other plaintiffs to the assault-style firearms definition, under the Second and Fourteenth Amendments and, for vagueness, the Fifth and Fourteenth Amendments. The Commonwealth answered on October 24, 2025, asserting sovereign immunity as its first defense. The case was consolidated into Capen on October 20, 2025.
• Commonwealth v. Thomson (SJC-13856): Decided October 20, 2026. The SJC held that the age-21 requirement for a license to carry in Section 131(d)(iv) is consistent with the nation's historical tradition of firearm regulation and affirmed the conviction. The as-applied challenge was not reached because the defendant had never applied for a license.^[11]
• Granata v. Campbell (First Circuit): Challenges the Massachusetts Approved Handgun Roster and AG handgun sales regulations. The United States filed an amicus brief on January 28, 2026 supporting the challengers, and the First Circuit heard argument on September 9, 2026 (No. 25-1918).