California's AB 2047 Would Require Firearm Blocking Technology on All 3D Printers

California wants 3D printers to block gun files before they leave the factory

A bill working its way through the California Legislature could reshape how 3D printers are sold in the state. AB 2047, which passed a Senate committee on August 13 and was amended again on August 17, would require manufacturers to equip printers with firearm blueprint detection technology by 2029.

The bill specifically targets the ability to detect and block files designed to produce firearms. It does not ban 3D printers outright, but it would make it illegal to sell or transfer any printer in California that lacks the required blocking technology, unless the model appears on a Department of Justice compliance list.

What the bill actually requires

Under AB 2047, the California Department of Justice must publish performance standards for firearm blueprint detection algorithms by September 1, 2028. Manufacturers then have until March 1, 2029 to submit attestations confirming each of their models includes the technology. Starting June 1, 2029, the DOJ will publish a public list of compliant and non-compliant models. Beginning December 1, 2029, selling a non-compliant printer becomes unlawful.

The blocking technology can take several forms: hardware, firmware, or other integrated measures capable of detecting firearm-related blueprints. The bill does not demand 100% accuracy, which is just as well because industry observers say perfect detection is impossible with current software.

Why the maker community is worried

Adafruit, a major marketplace for DIY electronics and 3D printer parts, has criticized the bill as an overreach. The company argues that accurately identifying gun parts from geometry alone is incredibly hard, that desktop printers lack the processing power to run meaningful analysis, and that open-source firmware makes any blocking requirement easy to bypass.

Adafruit's broader concern is the precedent. A state-maintained roster of approved printer models could restrict which machines makers can buy, and the requirement to install surveillance software could extend beyond firearms to other file types later.

Where things stand

AB 2047 was read a second time in the Senate on August 17 and ordered to third reading. If it passes the Senate and is signed by the governor, it would become one of the strictest 3D printer regulations in the United States. The December 2029 effective date gives manufacturers time to comply, but the attestation and listing process starts in 2029, meaning product roadmaps could shift well before then.

For California retailers and consumers, the practical impact is clear: by late 2029, the selection of 3D printers available in the state may look different from what is on the market today.