What is microstamping and how does it affect which handguns are sold in California?

Penal Code 32000 makes it a crime, punishable by up to one year in county jail, to manufacture, import for sale, keep for sale, offer for sale, give, or lend an "unsafe handgun" in California. DOJ keeps a roster of handguns that have passed testing and may be sold. Section 32000 lists exemptions, including curios or relics and sales to law enforcement agencies.

Penal Code 31910 defines "unsafe." Every handgun must pass firing and drop safety tests. A semiautomatic pistol that is not already on the roster must also have:

• A chamber load indicator, for centerfire pistols.
• A magazine disconnect mechanism, for centerfire or rimfire pistols with a detachable magazine.

Section 31910(b) also tells DOJ to remove three older pistols that lack those features for each new semiautomatic pistol added.

For years the roster test also required microstamping on new semiautomatic pistols. AB 2847, signed in 2020, cut the requirement from two imprint locations to one, effective July 1, 2022, and added the three-for-one removal rule.

SB 452, signed September 26, 2023, removed microstamping from section 31910 entirely. In its place it created a new, staged program in Penal Code sections 27531 to 27533, described on the DOJ SB 452 page.

Penal Code 27532 sets a chain of steps for DOJ. Each later step depends on the first finding.

1. Viability study, due March 1, 2025. DOJ released its report on July 18, 2025, and found the technology viable, according to the DOJ SB 452 page.
2. Performance standards, due September 1, 2025. DOJ's page points to regulations at title 11, sections 4600 and 4601.
3. Licensing of parts producers, starting by January 1, 2026.
4. Grants or contracts with producers, by July 1, 2026.
5. Availability decision, by July 1, 2027. DOJ must decide whether parts are available at commercially reasonable prices, or whether microstamping-enabled pistols are readily available for purchase in California.

If DOJ makes that availability finding, Penal Code 27533 makes it unlawful, starting January 1, 2028, for a licensed dealer to sell or transfer a semiautomatic pistol unless it is certified as microstamping-enabled. The section does not apply to a pistol manufactured or delivered to a dealer before January 1, 2028, or to private party transfers processed through a dealer.

As of 2026-11-10, the DOJ page does not report an availability decision.

Both cases challenge the Unsafe Handgun Act under the Second Amendment, and both are pending at the Ninth Circuit with no decision.

• Boland v. Bonta, No. 23-55276. A federal district court issued a preliminary injunction on March 20, 2023. On March 31, 2023, the Ninth Circuit stayed that injunction as to the chamber load indicator and magazine disconnect requirements, so those two requirements remain in force. The case was argued August 23, 2023. Submission was vacated on March 25, 2024, pending the en banc decision in Duncan v. Bonta, and the court ordered supplemental briefs on March 27, 2025. The docket shows no ruling since.
• Renna v. Bonta, No. 23-55367. Argued the same day before the same panel, with the same later orders. The most recent filings on the docket are supplemental authority letters from July 2026.

AB 1127, signed October 10, 2025, is a separate rule. Since July 1, 2026, Penal Code 27595 bars dealers from selling a "machinegun-convertible pistol," defined in Penal Code 16885 by its cruciform trigger bar design.

The two laws meet at the roster. AB 1127 lets a maker redesign an affected pistol that was on the roster on January 1, 2026, and resubmit it without adding a chamber load indicator or magazine disconnect, if it is submitted for testing before January 1, 2027.