Livestock Microchipping Laws in California: What Every Producer Needs to Know

If you raise cattle, horses, sheep, or goats in California, the rules around livestock identification have changed significantly — and the distinction between a subcutaneous microchip and an RFID ear tag matters more than ever. California producers now operate under a layered system: state-level brand and identification requirements administered by the California Department of Food and Agriculture (CDFA), and a federal electronic identification mandate that took effect in November 2024.

Understanding exactly where a microchip qualifies as official ID — and where it does not — can mean the difference between a smooth interstate shipment and an animal turned away at the border. This guide walks you through every layer of the rules so you can make informed decisions for your operation.

Microchipping vs. RFID Ear Tags: What Counts as Official ID in California

The terms “microchip” and “RFID” are often used interchangeably, but California and federal regulators draw a sharp line between them. Electronic Identification Devices (EID) is another term for RFID, and microchipping — or “chipping” — refers specifically to the microchip transponder implant placed under the skin. Both technologies use passive radio-frequency identification, but they serve different official purposes depending on species.

Externally attached microchips such as RFID ear tags are commonly used to identify farm and ranch animals, with the exception of horses. For cattle and bison moving interstate, the federal Animal Disease Traceability (ADT) framework treats RFID ear tags — not subcutaneous implants — as the primary form of official electronic identification. Subcutaneous microchips, by contrast, are the standard for equines and are accepted as official ID for horses, mules, and burros in California.

Official identification devices must provide a unique identification number, be tamper evident, have a high retention rate, and bear the US shield. Whether a device is an ear tag or an implant, it must meet those baseline requirements before CDFA or USDA will recognize it for traceability purposes.

Pro Tip: Before purchasing any electronic ID device, confirm with your CDFA district office that the specific product is on the USDA-approved list. Approval status can change, and using an unapproved device means your animal may not meet official ID requirements at inspection.

For species-by-species guidance on which form of electronic ID applies to your animals, see the California livestock transport laws overview, which covers documentation requirements alongside identification rules.

The Federal RFID Mandate and What It Means for California Producers

As of April 26, 2024, USDA APHIS published its final Animal Disease Traceability (ADT) rule into the Federal Register regarding the use of electronic identification (EID) eartags as official identification in cattle and bison. The intent of these changes is to strengthen the ability of the US to quickly respond to significant animal disease outbreaks, as rapid traceability is critical to ensuring appropriate disease response and timely return to business continuity.

The updated ADT regulations, effective November 5, 2024, aim to enhance the nation’s ability to respond to and mitigate the impact of foreign or significant diseases affecting livestock. Cattle tags applied after November 5, 2024, must be both visually and electronically readable (RFID). This is a meaningful shift from the previous system, which allowed purely visual metal tags as official identification.

Official metal tags that conform to the National Uniform Eartagging System and were applied before the November 5, 2024, deadline will continue to be accepted. If your cattle already carried compliant visual tags before that date, those tags remain valid for the lifetime of the animal — you do not need to re-tag them.

California is directly aligned with this federal framework. Through the USDA, the California Department of Food and Agriculture (CDFA) is offering electronic identification (EID) eartags at no cost for use in cattle and bison to California-based producers, California licensed and Category II accredited veterinarians, and approved tagging sites. To access free tags, you need a Premises Identification Number (PIN).

CDFA also has a limited number of tag applicators and tag readers available for loan. Contact the CDFA Animal Health Branch at 916-900-5002 or email ahbfeedback@cdfa.ca.gov to check current availability.

Key Insight: The cost of an 840 RFID ear tag runs roughly $3 per head when purchased commercially. Federal and state programs offering no-cost tags exist specifically to offset this burden for smaller producers — take advantage of them before supplies run out each season.

If you move cattle across state lines as part of a grazing rotation, you may also qualify for a Pasture-to-Pasture Permit. This option is available for beef breeding herds moving for pasture over the course of one grazing season between California and one of the following states: Oregon, Nevada, and Idaho. Call the Animal Health Branch Permit Line at (916) 900-5052 for details.

Which Livestock Can Use a Microchip as Official Identification in California

Not every species follows the same identification rules. The table below summarizes which animals can use a subcutaneous microchip as official or supplemental ID in California, based on CDFA and USDA guidelines.

Species	Primary Official ID Method	Microchip (Subcutaneous) Accepted?	Notes
Cattle & Bison	RFID ear tag (840 series)	Not as primary official ID	EID ear tag required for interstate movement after Nov. 5, 2024
Horses, Mules, Burros	Subcutaneous microchip or brand	Yes — primary form for equines	CVI required for interstate movement; microchip supports ownership proof
Sheep & Goats	Scrapie program ear tag or 840 microchip	Yes — 840-ID microchip approved	Flock/Scrapie ID also required
Swine	Premises-based ID or ear tag	Limited — check with CDFA	Entry permit and CVI required for non-slaughter swine entering CA
Camelids (Llamas, Alpacas)	No mandatory ID required	Yes — 840-ID microchip accepted	CVI recommended; no mandatory entry requirements if disease-free

The 840-ID Official Microchip can be used in all equines, goats, sheep, alpaca, llama, elk, whitetail and other deer, etc. For cattle, however, a subcutaneous implant does not replace the RFID ear tag requirement for interstate movement — it may supplement it but cannot stand alone as official traceability ID.

Producers raising pigs on small or backyard operations should also review the backyard pig laws in California for local permit and zoning requirements that layer on top of state livestock ID rules.

When a Microchip Qualifies for Interstate Movement in California

Interstate movement is where the rules get most consequential. All dairy females and males born after March 11, 2013, exhibition and rodeo cattle, and sexually intact beef cattle 18 months of age and older must be officially identified before moving interstate. For these animals, only an approved RFID ear tag — not a subcutaneous microchip — satisfies the federal official ID requirement.

For equines, the situation is different. Horses moving interstate from California need a Certificate of Veterinary Inspection (CVI), and a microchip supports the identity verification process during that inspection. An option for owners of horses traveling frequently between California and other states is the Extended Equine Certificate of Veterinary Inspection (EECVI). An EECVI is valid for up to six months and can be used for interstate movement instead of a traditional CVI, which is valid for 30 days from the date of inspection.

An entry permit and CVI are required for non-slaughter sheep and goats. An entry permit and CVI are required for non-slaughter swine. For sheep and goats, a 840-ID microchip can serve as the individual animal identifier on those documents, provided you also hold a valid Flock/Scrapie ID from USDA.

It is important to verify entry requirements of the destination state before moving livestock and poultry in order to ensure that shipments comply with interstate movement laws and regulations. California’s rules govern what leaves the state, but the receiving state sets its own entry requirements — those may be stricter or more permissive than California’s baseline.

Important Note: A microchip alone does not replace a Certificate of Veterinary Inspection for any species moving interstate from California. The chip establishes identity; the CVI certifies health status. Both are required for most species crossings.

For a full breakdown of documentation, permits, and route requirements, see the guide on transporting livestock in California.

Approved Microchip Standards and Placement by Species in California

California follows USDA and ISO standards for microchip technology. RFID technology used in the identification of animals is governed by two international standards — ISO 11784 and ISO 11785. ISO 11784 defines the code structure of the ID data, which is embedded in the memory of the transponder’s microchip. Any chip used as official livestock ID must comply with both standards.

For the RFID ear tag side of the equation, approved devices for EIDs include 134.2 kHz LF RFID tags compliant with both the 11784 and 11785 ISO standards, or UHF RFID tags. For subcutaneous implants used in horses and small ruminants, the same ISO frequency and code-structure standards apply.

The chip numbers begin with the official United States country code of 840. This 15-digit format — starting with 840 — is mandatory for any device used as official USDA identification, whether it is an ear tag or an injectable implant.

Placement guidelines by species are as follows:

• Cattle and Bison: RFID tags are recommended to be placed in the left ear.
• Horses, Mules, and Burros: Injectable microchips are typically placed in the nuchal ligament area of the neck (left side), following standard equine veterinary practice.
• Sheep and Goats: The 840-ID microchip is injected subcutaneously, commonly in the ear or base of the neck, per USDA scrapie program guidance. The FDA’s Center for Veterinary Medicine has approved the 840-ID Microchip for use in sheep and goats.
• Camelids (Llamas, Alpacas): The 840-ID microchip is accepted; placement follows manufacturer and veterinary guidance, typically in the left ear or neck area.

APHIS does not recommend specific tag providers, but tag companies may submit specific products — encoded with a 15-digit official ID number beginning with “840,” the ISO country code for the United States — to APHIS for approval. Always verify that the specific product you purchase appears on the USDA APHIS approved device list before implanting or applying.

Producers raising backyard chickens or other small poultry should note that electronic ID requirements differ entirely for birds — see the backyard chicken laws in California for poultry-specific rules.

Registering a Livestock Microchip in California

Implanting a chip is only half the job. Registration ties the chip number to your operation, your Premises Identification Number (PIN), and your animal’s records — and without that link, the chip provides little traceability value in a disease investigation or theft case.

A Premises Identification Number (PIN) is a unique alphanumeric number assigned to a geographic location where livestock or poultry are managed or other locations associated with animal agriculture. PINs are permanently assigned to a single location and must match the “911” address/physical location of the animals.

Here is the step-by-step registration process for California producers:

1. Obtain a PIN. To request a PIN, complete AHB Form 76-196-W (Location Number Request) and submit it to either your local AHB district office or the contact listed on the application.
2. Order approved 840-series devices. To obtain EID eartags through CDFA or the tag manufacturer directly, you must have a Premises ID Number (PIN). The same requirement applies to 840-ID injectable microchips for equines and small ruminants.
3. Have the chip applied by a licensed veterinarian. For subcutaneous implants, a Category II accredited veterinarian applies the chip and records the number on the animal’s health documentation.
4. Log the application. CDFA provides recordkeeping templates, including an EID Tag Application Log for Producers. Keep a copy for your own records and submit required reports to CDFA.
5. Maintain records for five years. Any person receiving livestock and owners of the shipped animals must maintain official documents for five years.

To use 840-series chips, you must have a Premises ID. If you raise goats or sheep, you must also have a Flock/Scrapie ID. You can request both through CDFA’s Animal Health Branch or directly through USDA APHIS.

For questions about disease reporting obligations that accompany your identification records, the livestock disease reporting requirements in California page covers mandatory notification timelines and which conditions trigger a report.

Microchipping as Proof of Ownership in California

California’s livestock identification system has historically centered on brands rather than electronic chips. The state’s brand registration and inspection program protects cattle owners in California against loss of animals by theft, straying, or misappropriation. The program consists of registration of cattle, horse, burro, and sheep permanent brands; inspection of cattle for lawful possession prior to movement, sale, or slaughter; and assisting local law enforcement with investigations and prosecutions involving cattle theft.

A registered brand remains the strongest standalone proof of cattle ownership under California law. However, a microchip or RFID ear tag strengthens an ownership claim in several important ways:

• The chip number is tied to your PIN and recorded in CDFA’s system, creating a timestamped digital ownership record.
• For horses, mules, and burros — which are not subject to mandatory brand inspection — a microchip is often the most reliable permanent identifier available.
• In theft or dispute cases, a chip number linked to your premises record provides documentation that a brand alone cannot if the brand has been altered or is absent.

A CDFA inspector shall seize any bovine animal, horse, mule, or burro — or the hide or carcass of any such animal — found in the possession of a person who cannot prove ownership. A readable microchip registered to your PIN is one of the fastest ways to establish that proof at an inspection stop.

Once an animal is injected with the chip, it can be identified throughout its life by this one-of-a-kind number. Its identification cannot be lost, altered, or intentionally removed. That permanence is what makes subcutaneous microchips particularly valuable for horses and small ruminants, where external tags can fall out or be removed.

For cattle, the brand inspection system and RFID ear tag work together. All cattle must be brand inspected when it is required, whether or not they have a brand. An RFID ear tag reading that matches your PIN record can expedite that inspection and reduce the risk of a disputed ownership finding.

Pro Tip: If you sell livestock privately, document the chip or tag number on the bill of sale alongside the brand description. California regulations require records to include the animal’s identification, the buyer, and the seller — a chip number satisfies the identification element cleanly.

Ownership documentation matters beyond the farm gate too. If you keep livestock in a shared or leased facility, your chip registration through CDFA ties the animal to your PIN — not the property owner’s. That distinction can be critical if a dispute arises. For broader context on how California law handles animal ownership disputes, see the pet custody laws in California and the animal cruelty laws in California, which also address seizure and ownership standards for animals in distress.

California’s livestock identification rules sit at the intersection of federal traceability law and state brand-inspection authority. Keeping your PIN current, using only USDA-approved 840-series devices, and maintaining five years of records puts you in compliance with both frameworks — and gives you the documentation you need if your animals are ever lost, stolen, or challenged at an inspection point. Contact the CDFA Animal Health Branch at 916-900-5002 or visit the CDFA Animal Disease Traceability page to order free EID tags, request a PIN, or find your nearest approved tagging site.