Date saved: 2026-10-24 18:01 (PDT)
Sources: California Legislature, Washington State Legislature, Colorado Legislature, EFF, Giffords Law Center, 3D Printing Industry, The Verge, Tom's Hardware, Adafruit, Stateline, Mother Jones
Key findings
State laws requiring printer blocking technology
- California Governor Gavin Newsom signed legislation making California the second U.S. state to mandate firearm-blocking technology in 3D printers sold within its borders, following a similar measure in New York. The law takes effect only after ASTM International publishes or adopts a technical standard for the blocking technology, with the California Department of Justice checking quarterly starting July 1, 2027, and the monitoring obligation lapsing if no standard appears by July 1, 2029. (Source)
- The California law, AB 2047, requires the state Department of Justice to maintain an approved roster of 3D printer makes and models equipped with firearm-blocking technology, and manufacturers who want to sell printers in the state must attest that they have implemented a firearm detection algorithm approved by the government. Civil penalties can reach $25,000 per violation for printers sold after December 1, 2029, that do not appear on the approved list. (Source)
- New York became the first state to require 3D printers to scan what users make and decide whether they are allowed to make it, with blocking-technology requirements signed into law on May 27, 2026. The device requirement awaits a state task force, and the law defines its scope to include CNC mills, automated routers, and lathes. (Source)
- Adafruit's analysis found that New York's language covers not just additive printers but CNC mills, and in their reading, any machine capable of making three-dimensional modifications to an object from a digital file using subtractive manufacturing. (Source)
Criminalizing the output and the files
- Colorado's HB 26-1144, signed into law and effective July 1, 2026, prohibits knowingly manufacturing or producing a potentially functioning firearm, unfinished frame or receiver, large-capacity magazine, or rapid-fire device by 3D printing, defining 3D printing to mean both additive and subtractive manufacturing. A first offense is a class 1 misdemeanor, and a second or subsequent offense is a class 5 felony. (Source)
- Washington's HB 2320, signed into law with an effective date of March 24, 2026, prohibits manufacturing a frame or receiver or an unfinished frame or receiver by use of a 3D printer or CNC milling machine unless the person is licensed to manufacture firearms under federal law. It also prohibits selling, transferring, or distributing digital firearm manufacturing code to anyone not licensed to manufacture firearms. (Source)
- Washington's law defines "digital firearm manufacturing code" as any digital instructions in the form of CAD files or other code stored and displayed in electronic format as a digital model that may be used to program a 3D printer or a CNC milling machine to manufacture a firearm, frame or receiver, magazine, or unlawful firearm part. (Source)
- California law requires any person, firm, or corporation to obtain a firearm manufacturer's license to use a 3D printer to manufacture any number of firearms, and similarly requires a federal license to use a CNC milling machine to manufacture a firearm, including a completed or unfinished frame or receiver. (Source)
The blocking technology debate
- The EFF has argued that print-blocking cannot work reliably, because a database-matching approach can be defeated by modifying a file, such as changing its size or splitting it into pieces, while an AI-based detection approach is prone to false positives that could prevent printing of legitimate parts like barrels, brackets, levers, tubes, and other components. (Source)
- At least 16 states have laws addressing 3D-printed firearms, with 7 adding major legislation in 2026, according to Stateline reporting cited in an investigation. (Source)
- The Federal NDAA FY2026 and HR 4143 have also addressed 3D-printed firearm issues at the federal level, alongside the state-level bills. (Source)
- A federal jury convicted a Harrisburg, Illinois man on five gun-related charges after agents raided his home and seized three 3D printers, a CNC milling machine, a Ghost Gunner milling machine, and a drill press with firearm-specific jigs. (Source)
International and broader context
- The laws in California, New York, Washington, and Colorado are part of a wider pattern of treating fabrication tools themselves as regulatory choke points, a model that critics compare to locked-down cars and tractors, where owners lose the ability to modify or repair their own equipment. (Source)
- Existing 3D printers are exempt from the California and New York blocking requirements; there is no retrofit mandate, and someone who already owns a printer without blocking technology can continue using it. The restrictions apply to new sales and transfers. (Source)
A new legal strategy for controlling homemade firearms has arrived, and it does not target the guns or the people making them. It targets the machines. California, New York, Washington, and Colorado have all moved laws that regulate 3D printers and CNC milling machines as points of enforcement in firearms policy, with California and New York specifically requiring "firearm-blocking" technology in printers sold within their borders. The approach is a direct response to the practical failure of earlier bans: criminalizing the manufacture of 3D-printed guns has proven nearly impossible to enforce because the printing happens in private, and distributing digital CAD files to anyone who can print them is hard to stop.
What makes this wave different from earlier restrictions is the reach of the machine definitions. New York's law, analyzed by Adafruit, reaches CNC mills and subtractive-manufacturing machines, not just 3D printers. Washington's law defines "digital firearm manufacturing code" to include any instructions that may be used to program a CNC milling machine. Colorado's bill defines 3D printing to include both additive and subtractive manufacturing. The practical effect is that a lathe, a router, and a milling machine used in a home workshop or a school shop class can fall under the same legal umbrella as a desktop 3D printer, depending on how they are marketed and what they are capable of making from a digital file. The EFF, Adafruit, and the Firearms Policy Coalition have all argued the blocking technology is technically infeasible, and that it will lock makers into proprietary, surveilled hardware.
Source links
- EFF: Print Blocking Won't Work - Permission to Print Part 2
- 3D Printing Industry: California's 3D Printer Gun Law Signed
- The Verge: Are you ready for what it takes to stop ghost guns?
- Tom's Hardware: California bill requiring 3D printers to block firearm printing becomes law
- Colorado Legislature: HB 26-1144 Prohibit 3D Printing Firearms & Components
- Washington State Legislature: HB 2320 Session Law
- Giffords Law Center: Ghost Guns in California
- Adafruit analysis: They're Putting a Kill Switch in Your 3D Printer
- News 4 Makers: Background checks for 3D printers
- The New York Gun Ban is Coming for Your 3d Printer