CA AB2156

Prohibits any person from manufacturing more than three firearms within California in a calendar year without a state manufacturer's license, regardless of federal licensure status.

Lowers the manufacturing threshold requiring state licensure from 50 firearms to 4 or more firearms per calendar year.

Prohibits manufacturing any firearm, frame, receiver, or firearm precursor part using a three-dimensional printer without a state manufacturer's license.

Defines "three-dimensional printer" as a computer-aided manufacturing device capable of producing three-dimensional objects through additive manufacturing by layering two-dimensional cross sections of resin or similar material.

Establishes violations of these requirements as misdemeanors and specifies that no state reimbursement is required for local compliance costs.