CALIFORNIA LEGISLATURE— 2025–2026 REGULAR SESSION

Assembly Bill

No. 2047

Introduced by Assembly Member Bauer-Kahan

February 17, 2026

An act to add Title 21.1 (commencing with Section 3273.631) to Part 4 Division 3 of the Civil Code, and to add Section 29187 to the Penal Code, relating to firearms.

LEGISLATIVE COUNSEL'S DIGEST

AB 2047, as introduced, Bauer-Kahan. Firearms: 3-dimensional printing blocking technology.

Existing law makes it a crime to knowingly or willfully cause another person to engage in the unlawful manufacture of firearms or knowingly or willfully aiding, abetting, prompting, or facilitating the unlawful manufacture of firearms, including the manufacture of assault weapons or .50 BMG rifles or the manufacture of any firearm using a 3-dimensional printer, as specified.

This bill would require the Department of Justice or other relevant state agency to engage in an investigation of known firearm blueprint design files and existing firearm blueprint detection algorithms, as defined. The bill would require, on or before July 1, 2027, the department or other relevant state agency to publish written guidance on performance standards for persons or entities engaged in the creation of firearm blueprint detection algorithm to be certified for use by 3-dimensional printer manufacturers, as specified. The bill would require the department or other relevant state agency that prepared the written guidance on performance standards to accept applications for certification of firearms blueprint detection algorithms and begin issuing certifications of algorithms that meet or exceed the performance standards on or before January 1, 2028, and would specify the grounds for revocation of certification pursuant to these provisions. The bill would require the department or other relevant state agency to publish written guidance on how to equip 3-dimensional printers with firearm blocking technology, as defined, and would require the performance standards to be publicly available on the department or other relevant state agency’s website.

This bill would require, on or before July 1, 2028, any business that produces or manufactures 3-dimensional printers for sale or transfer in California to submit to the department an attestation for each make and model of printer they intend to make available for sale or transfer in California, confirming, among other things, that the manufacturer has equipped that make and model with a certified firearm blueprint detection algorithm. If the department verifies a printer make and model is properly equipped, the bill would require the department to issue a notice of compliance, as specified. The bill would require, on or before September 1, 2028, the department to publish a list of all the makes and models of 3-dimensional printers whose manufacturers have submitted complete self-attestations and would require the department to update the list no less frequently than on a quarterly basis and to make the list available on the department’s internet website. The bill, beginning on March 1, 2029, would prohibit the sale or transfer of 3-dimensional printers that are not equipped with firearm blocking technology and that are not listed on the department’s list of manufacturers with a certificate of compliance verification, except as specified. The bill would authorize a civil action to be brought against a person who sells, offers to sell, or transfers a printer without the firearm blocking technology.

This bill would also make it a crime to knowingly disable, deactivate, uninstall, or otherwise circumvent any firearm blocking technology installed in a 3-dimensional printer with intent to manufacture firearms or to distribute, sell, or transfer for consideration in California one or more modified versions of a 3-dimensional printer identified on the Department of Justice’s list of 3-dimensional printers eligible for sale in California. By creating a new crime, this bill would impose a state-mandated local program.

This bill would make these provisions severable.

The California Constitution requires the state to reimburse local agencies and school districts for certain costs mandated by the state. Statutory provisions establish procedures for making that reimbursement.

This bill would provide that no reimbursement is required by this act for a specified reason.

Vote: MAJORITY Appropriation: NO Fiscal Committee: YES Local Program: YES

The people of the State of California do enact as follows:

SECTION 1.

Title 21.1 (commencing with Section 3273.631) is added to Part 4 of Division 3 of the Civil Code, to read:

TITLE 21.1. Firearm Printing Prevention Act

3273.631.

This title shall be known, and may be cited, as the California Firearm Printing Prevention Act.

3273.632.

As used in this title, the following definitions shall apply:

(a) “Department” means the Department of Justice.

(b) “Firearm” has the same meaning as defined in subdivision (a) of Section 16520 of the Penal Code.

(c) “Firearm blocking technology” means hardware, firmware, or other integrated technological measures capable of ensuring a three-dimensional printer will not proceed to any print job unless the underlying three-dimensional printing file has been evaluated by a firearms blueprints detection algorithm and determined not to be a printing file that would produce a firearm or illegal firearm parts.

(d) “Firearm blueprint detection algorithm” means a software service that evaluates three-dimensional printing files, whether in the form of stereolithography (STL) files or other computer-aided design files or geometric code, to determine if the files can be used to program a three-dimensional printer to produce a firearm or illegal firearm parts, and flag any such files to prevent their use to manufacture a firearm or illegal firearm parts.

(e) “Firearm precursor part” has the same meaning as defined in Section 16531 of the Penal Code.

(f) “Firmware design” means integration of a firearms blueprint detection algorithm directly into a three-dimensional printer’s firmware, such that any geometric code received by the printer must be evaluated by the algorithm before the printer will proceed to print, and such that the printer will reject print jobs identified by the algorithm because they would direct the printer to print firearms or illegal firearm parts.

(g) “Illegal firearm parts” means a firearm precursor part and any part designed and intended for use in converting a semiautomatic weapon into a machine gun, including, but not limited to, a pistol convertor.

(h) “Integrated pre-print software design” means a limitation of a three-dimensional printer’s operation to accept geometric code for printing exclusively from a single slicer or other preprint software, which may be the manufacturer’s proprietary software, and integration of a firearms blueprint detection algorithm into that preprint software, such that any STL file or other computer-aided design file must be evaluated by the algorithm before the software will proceed to produce geometric code, and such that the software will not produce geometric code for files that are identified by the algorithm because they would direct the printer to print firearms or illegal firearm parts.

(i) “Pistol convertor” has the same meaning as defined in Section 17015 of the Penal Code.

(j) “Software controls process” means a system designed to stop a three-dimensional printer from initiating any print job unless the underlying three-dimensional printing file has been evaluated by a firearms blueprints detection algorithm and determined not to be a printing file that would produce a firearm or illegal firearm parts.

(k) “Three-dimensional printer” has the same meaning as subdivision (d) of Section 3273.60.

3273.633.

(a) The department or other relevant state agency shall engage in an investigation of known firearm blueprint design files and existing firearm blueprint detection algorithms. The department or other relevant state agency may create, maintain, and regularly update a library of firearm blueprint files and illegal firearm parts blueprint files for use by firearm blueprint detection algorithm designers, or may coordinate with another government agency or major research institution, including, but not limited to, a University of California academic department, to create, maintain, and regularly update a library with safeguards to prevent unauthorized access to, or misuse of, the library.

(b) (1) On or before July 1, 2027, the department or other relevant state agency shall publish written guidance on performance standards for persons or entities engaged in the creation of firearm blueprint detection algorithms to be certified for three-dimensional printer manufacturer use in complying with Sections 3273.636 and 3273.637.

(2) The department or other relevant state agency may seek input from relevant stakeholders and technical experts in the process of preparing written guidance on performance standards for firearm blueprint detection algorithms.

(3) The performance standards shall require that firearm blueprint detection algorithms have the capacity, with a high degree of accuracy, to do all of the following:

(A) Evaluate three-dimensional printing files, whether in the form of STL files or other computer-aided design files or geometric code.

(B) Detect and identify any such files that can be used to program a three-dimensional printer to produce a firearm or illegal firearm parts.

(4) The performance standards shall require that, at a minimum, firearm blueprint detection algorithms have the capacity to utilize an inventory of disallowed firearm blueprint files that have been commonly downloaded or shared on public internet forums to detect those files and modified versions of those files.

(5) The department or other relevant state agency shall not require that a firearm blueprint detection algorithm produce a perfect success rate at detecting disallowed files.

(6) The department or other relevant state agency preparing the written guidance on performance standards shall include performance standards requiring that the firearm blueprint detection algorithm have the capacity to implement regular updates to the set of disallowed firearm files it has the capacity to detect, to an extent and with a frequency to be determined by the department that accounts for the rate of innovation for the design and availability of new firearm blueprint files.

(7) The department or other relevant state agency preparing the written guidance on performance standards shall periodically review emerging detection software techniques, including, but not limited to, advanced forms of image recognition and pattern analysis as well as volumetric search functionality. If, at any time, the department or other relevant state agency preparing the written guidance on performance standards determines that a novel technique with a substantially higher degree of performance is available to be utilized by algorithms already certified under subdivision (c), the department or other relevant state agency preparing the written guidance on performance standards may require that previously certified algorithms update their technology to match or exceed the performance of that novel technique. Any vendor with a previously qualified algorithm who is required to make that update shall have a reasonable period of time, not less than three months, to update their previously qualified algorithm.

(c) (1) On or before January 1, 2028, the department or other relevant state agency that prepared the written guidance on performance standards described in this section shall accept applications for certification of firearms blueprint detection algorithms and begin issuing certifications of algorithms that meet or exceed the performance standards described in subdivision (b).

(2) For purposes of evaluating applications for firearm blueprint detection algorithm certification, the department or other relevant state agency that prepared the written guidance on performance standards described in this section shall require applicants to satisfy both of the following:

(A) Identify the inventory of firearm blueprint files used to design the algorithm so that the department or other relevant state agency evaluating applicants may assess and confirm that the file inventory is sufficiently thorough.

(B) Provide access for testing, as well as schematics or other detailed explanation of their technology sufficient for the department or other relevant state agency evaluating applicants to evaluate its suitability for certification.

(3) The list of firearm blueprint detection algorithms that have received certification as meeting or exceeding performance standards shall be made publicly available on the internet website of the department or other relevant state agency issuing certification.

(d) The department or other relevant state agency issuing certification shall revoke certification for a firearms blueprint detection algorithm if, at any time, it fails to meet the performance standards for certification, including, without limitation, failure by a certified algorithm to implement regular updates to its inventory of disallowed files as required by the department or relevant state agency, or to update its technology to match the state-of-the-art performance of an emerging detection technique as required by the department in paragraph (7) of subdivision (b). In the event of a revocation pursuant to this section, the department or relevant state agency shall notify relevant printer manufacturers with printer models known to use that algorithm that an algorithm they have deployed is no longer certified, and the manufacturer shall have a reasonable period, not less than three months, to update their model and resubmit their attestation of use of certified blocking technology, as described in Section 3273.636.

3273.634.

(a) The department or relevant state agency shall engage in an investigation of existing software controls processes available for use in three-dimensional printers for the purpose of preventing three-dimensional printing of firearms and illegal firearm parts.

(b) (1) On or before July 1, 2027, the department or relevant state agency shall publish written guidance on performance standards for persons or entities engaged in the creation of software controls processes to be certified for three-dimensional printer manufacturer use in complying with Sections 3273.636 and 3273.637.

(2) The department or other relevant state agency preparing the written guidance on performance standards may seek input from relevant stakeholders and technical experts in the process of preparing written guidance on performance standards for software controls processes, including from persons who provide software, firmware, or other services integral to establishing software controls processes for three-dimensional printers.

(3) The performance standards shall require that software controls processes have the capacity, to a high degree of reliability, to effectively prevent a technically skilled user from evading a firearms blueprint detection algorithm.

(4) The department shall not require that a software controls process produces a perfect success rate at preventing a user from evading a firearms blueprint detection algorithm.

(5) The performance standards shall set out options for design forms that may be used for a software controls process integration into a three-dimensional printer, including all of the following:

(A) Firmware design.

(B) Integrated preprint software design.

(C) Any other form, including, but not limited to, handshake authentication design, if the department first determines that the software controls process is both of the following:

(i) At least as effective in ensuring no print jobs can proceed unless they are evaluated by a firearm blueprint detection algorithm as the design forms described in subparagraphs (A) and (B).

(ii) At least as resistant to being defeated by a technically skilled user as the design forms described in subparagraphs (A) and (B).

(6) The written guidance shall include both of the following:

(A) For firmware design, guidance for how vendors are required to demonstrate that their technology will ensure a printer directs potential print jobs to the algorithm before printing can occur.

(B) For integrated preprint software design, guidance for how vendors shall demonstrate that printers will accept print jobs exclusively from a single preprint software and will not accept print jobs from any other preprint software, including from a user seeking to evade a detection algorithm.

(c) On or before January 1, 2028, the department or other relevant state agency that prepared the written guidance on performance standards described in this section shall accept applications for certification of software controls processes and begin issuing certifications of software controls processes that meet or exceed the performance standards described in subdivision (b).

(d) For purposes of evaluating applications for certification, the department or other relevant state agency evaluating applicants shall require applicants to provide software and hardware, as applicable, for testing by regulators, as well as schematics or other detailed explanation of their technology sufficient for the department to evaluate its suitability for certification.

(e) The list of software controls processes that have received certification as meeting or exceeding performance standards shall be made publicly available on the internet website of the department or other relevant state agency issuing certification.

(f) The department or other state agency that issued certification shall revoke certification for a software controls process if, at any time, it fails to meet the performance standards for certification. In that case, the department or other state agency that issued certification shall notify relevant printer manufacturers with printer models known to use that software controls process that a software controls process they have deployed is no longer certified, and the manufacturer shall have a reasonable period, not less than three months, to update their model and resubmit their attestation of use of certified blocking technology, as described in Section 3273.636.

3273.635.

(a) On or before March 1, 2028, the department or other relevant state agency shall publish written guidance on performance standards for manufacturers of three-dimensional printers on how to equip printers with firearm blocking technology. This guidance shall include all of the following:

(1) Performance standards for equipping three-dimensional printers with a certified firearm blueprint detection algorithm and where to find updated lists of certified firearm blueprint detection algorithms published by the department.

(2) Performance standards for equipping three-dimensional printers with a certified software controls process and where to find updated lists of certified software controls processes published by the department.

(3) Performance standards on how to test functionality of the certified firearm blueprint detection algorithm and software controls process to meet a specified degree of reliability in blocking the printing of firearms or illegal firearm parts.

(b) The performance standards described in subdivision (a) shall be made publicly available on the internet website of the department or the state agency that prepared the written guidance on performance standards described in this section.

3273.636.

(a) (1) On or before July 1, 2028, any business that produces or manufactures three-dimensional printers for sale or transfer in California shall submit to the department an attestation form for each make and model of printer they intend to make available for sale or transfer in California.

(2) The self-attestation shall include all of the following information:

(A) The make and model of the three-dimensional printer.

(B) Confirmation that the manufacturer has equipped that make and model with a certified firearm blueprint detection algorithm and which certified firearm blueprint detection algorithm from the list published pursuant to Section 3273.633 was used.

(C) Confirmation that the manufacturer has equipped that make and model with a certified software controls process and which certified software controls process from the list published pursuant to Section 3273.634 was used.

(D) Confirmation of testing the functionality of the certified firearm blueprint detection algorithm and software controls process once installed according to performance standards issued by the department pursuant to Section 3273.635.

(3) If the self-attestation form is incomplete or contains information indicating the make and model of printer identified may not be effectively equipped with firearm blocking technology, the Attorney General has authority to investigate and inspect the submission, including, but not limited to, requesting sample models from the manufacturer to verify the attestation of compliance. Any make and model of three-dimensional printer actively under investigation and inspection shall be identified as having an incomplete attestation on the list described in subdivision (c).

(b) (1) On or before July 1, 2028, the department shall begin accepting applications from three-dimensional printer manufacturers for a voluntary verification of their self-attestation, allowing the department to inspect and confirm that a specific make and model of printer complies with the performance standards described in subdivision (a).

(2) If the department verifies a printer make and model is properly equipped with firearm blocking technology, the department shall issue to the manufacturer a written notice of compliance verification for the make and model, which shall constitute compliance with subdivision (a) of Section 3273.637.

(3) No manufacturer of a printer for which a written notice of compliance verification has been issued under this subdivision shall be subject to civil actions under Section 3273.637. This subdivision does not apply to a manufacturer who received notice from the department that the previously verified model contained a firearms blueprint detection algorithm for which certification was revoked pursuant to subdivision (d) of Section 3273.633 or a software controls process for which certification was revoked under subdivision (d) of Section 3273.634, until the manufacturer updates their model and resubmits the model for an updated compliance verification.

(c) (1) On or before September 1, 2028, the department shall publish a list of all the makes and models of three-dimensional printers whose manufacturers have submitted complete self-attestations pursuant to subdivision (a), any makes and models of three-dimensional printers that have an incomplete attestation on file, any makes and models that have submitted for and received the voluntary compliance verification described in subdivision (b), and any makes and models that have a pending submission for voluntary compliance verification under subdivision (b).

(2) The lists shall be updated no less frequently than on a quarterly basis and made accessible on the department’s internet website. Retailers or distributors of three-dimensional printers shall consult the lists posted on the department’s internet website to ensure their inventory for sales in California consists of three-dimensional printers in compliance with this title.

(3) It shall be an affirmative defense to any action against a retailer, distributor, importer, wholesaler, or other individual transferor of a three-dimensional printer for an alleged violation of Section 3273.637 that the retailer, distributor, or other individual transferor only sold or transferred the three-dimensional printer after verifying that the make and model was listed by the department on the published list described in this section, and not designated as having an incomplete attestation.

3273.637.

(a) Any business that produces or manufactures three-dimensional printers for sale or transfer in California shall take both of the following steps:

(1) Before any three-dimensional printer is offered, sold, transferred, or distributed to any person or business in California, the manufacturer shall equip the three-dimensional printer with certified firearm blocking technology, as described in Sections 3273.633 and 3273.634.

(2) Before any three-dimensional printer is offered, sold, transferred, or distributed to any person or business in California, the manufacturer shall submit a self-attestation of installation of firearm blocking technology to the department, as described in Section 3273.636.

(b) Any business that sells, offers to sell, distributes, or transfers for consideration a three-dimensional printer in California shall consult the list published by the department described in subdivision (c) of Section 3273.636.

(c) It shall be unlawful to sell or transfer for consideration a three-dimensional printer in California that does not meet both of the following requirements:

(1) The three-dimensional printer shall be equipped with firearm blocking technology.

(2) The three-dimensional printer shall be listed by the department on the published list described in subdivision (c) of Section 3273.636 as having a complete attestation on file, having received a certificate of compliance verification, or having a pending application for a certificate of compliance verification.

(d) This section shall not apply to the following products:

(1) Printers manufactured for and sold exclusively to a state-licensed firearms manufacturer, as defined in subdivision (g) of Section 29185 of the Penal Code.

(2) Printers manufactured for and sold exclusively to the State of California or law enforcement agencies of the United States for the manufacturing of firearms for law enforcement or military purposes.

(3) Printers manufactured for and sold exclusively to aerospace, biomedical, automotive, or chemical or mechanical engineering companies or government contractors that are not also sold on the consumer retail market.

(e) A civil action may be brought against a person who does either of the following:

(1) (A) Sells, offers to sell, or transfers for consideration a three-dimensional printer in California that is not equipped with firearm blocking technology.

(B) It shall be an affirmative defense to any action against a retailer, distributor, wholesaler, importer, or other individual transferor of a three-dimensional printer for an alleged violation of this section that the retailer, distributor, wholesaler, importer, or other individual transferor only sold or transferred the three-dimensional printer after verifying that the make and model was listed by the department on the published list described in this section, and not designated as having an incomplete attestation.

(C) It shall be an affirmative defense to any action for violation of this paragraph that the department issued a written notice of compliance verification for the make and model of printer at issue.

(2) Knowingly files an attestation in subdivision (a) of Section 3273.636 containing false information. The filing of a civil action under this section shall not preclude potential criminal prosecution for perjury, as defined in Section 118 of the Penal Code.

(f) (1) A person who has suffered harm in California as a result of a violation of this section may bring an action in a court of competent jurisdiction to establish that a person has violated this section, and may seek compensatory damages as well as injunctive relief sufficient to prevent the person and any other defendant from further violating the law.

(2) The Attorney General, a county counsel, or a city attorney may bring an action in a court of competent jurisdiction to establish that a person has violated this section, and may seek a civil penalty not to exceed twenty-five thousand dollars ($25,000) for each violation, as well as injunctive relief sufficient to prevent the person and any other defendant from further violating the law.

(3) A prevailing plaintiff shall be entitled to recover reasonable attorney’s fees and costs.

(g) The remedies provided by this section are cumulative and shall not be construed as restricting any other rights, causes of action, claims, or defenses available under any other law.

(h) This section shall become operative on March 1, 2029.

3273.638.

The department may promulgate regulations and develop forms and publications necessary to implement this title.

SEC. 2.

Section 29187 is added to the Penal Code, to read:

29187.

(a) It is unlawful to knowingly disable, deactivate, uninstall, or otherwise circumvent any firearm blocking technology installed in a three-dimensional printer with intent to manufacture firearms or to distribute, sell, or transfer for consideration in California one or more modified versions of a three-dimensional printer identified on the Department of Justice’s list of three-dimensional printers eligible for sale in California, as described in Section 3273.636 of the Civil Code.

(b) A violation of this section is a misdemeanor.

SEC. 3.

The provisions of this act are severable. If any provision of this act or its application is held invalid, that invalidity shall not affect other provisions or applications that can be given effect without the invalid provision or application.

SEC. 4.

No reimbursement is required by this act pursuant to Section 6 of Article XIII B of the California Constitution because the only costs that may be incurred by a local agency or school district will be incurred because this act creates a new crime or infraction, eliminates a crime or infraction, or changes the penalty for a crime or infraction, within the meaning of Section 17556 of the Government Code, or changes the definition of a crime within the meaning of Section 6 of Article XIII B of the California Constitution.