Chapter 135 of the Acts of 2024 (H.4885)
In effect since October 2024, and on the ballot this November.
Last reviewed 2026-08-01
Chapter 135 of the Acts of 2024, originally House Bill 4885 and titled An Act Modernizing Firearm Laws, was signed by Governor Maura Healey on July 25, 2024. Key provisions took effect on October 23, 2024.
Massachusetts regulates the equipment directly, which most states do not. Using a 3D printer or CNC mill to make a firearm frame or receiver requires a License to Carry, and selling printers marketed for firearm production is prohibited outright.
Two dates matter now. On October 2, 2026, owners of previously printed or privately assembled firearms must have applied for state serial numbers, embedded a steel serialisation plate, and registered with DCJIS. After that date, possessing an unserialised 3D-printed frame or receiver becomes a felony.
On November 3, 2026, a statewide veto referendum, Question 9, asks voters whether to keep the law. Opponents gathered enough signatures to put the whole of Chapter 135 on the ballot, including every 3D printer and CNC provision in it. A YES vote keeps the law; a NO vote repeals it.
Illegal for any individual to use a 3D printer or CNC milling machine to make or assemble a firearm frame or receiver without a valid License to Carry.
Prohibits selling, offering for sale or transferring any 3D printer or CNC mill in Massachusetts whose primary or intended function is manufacturing firearms, defined by how the equipment is advertised, marketed or promoted.
Any privately made firearm produced by 3D printing must be assigned a unique serial number obtained electronically through DCJIS.
For non-metallic or plastic frames, the serial number must be permanently embedded in a metal plate cast into or joined to the material, engraved at least 0.003 inches deep with characters at least 1/16 inch high.
Bans manufacture, sale, transfer or possession of covert or undetectable 3D-printed firearms that defeat metal detectors or X-ray screening.
Representative Michael S. Day and Senator Cynthia Stone Creem
Joint Committee on the Judiciary
(617) 722-2396
Michael.Day@mahouse.gov