Every dog entering or returning to the United States must have a microchip. The chip does not need to be a particular brand, but it must be readable with a universal scanner.
The difficult part is not usually implantation. It is making sure the chip scans correctly, appears under the same number on every document, and was implanted early enough for any rabies-vaccination rules that apply to your dog’s route.
Current as of 2026: Dog-import and pet-travel rules can change. Check the CDC dog import requirements, the CDC Dog Import Form instructions, and the requirements for every country on your itinerary before traveling.
The Short Answer: What Does Your Dog Need?
For entry into the United States, your dog needs a microchip that can be detected with a universal scanner. CDC does not require a particular manufacturer.
Before traveling, make sure:
- The chip scans successfully.
- The scanned number matches your dog’s records.
- The same number appears on the CDC Dog Import Form and all required veterinary documents.
- Any travel-valid rabies vaccination was given in the correct order for your dog’s pathway.
- You have checked the origin and transit-country rules, not only the US rule.
As of 2026, all dogs entering the US must also appear healthy, be at least 6 months old, and have a CDC Dog Import Form receipt. Dogs that have been in a high-risk country for dog rabies during the previous 6 months need additional documents.
What a Dog Microchip Does
A standard pet microchip is a small identification device implanted under the skin. When a compatible scanner passes over it, the scanner displays the chip’s identification number.
The chip itself:
- Does not provide GPS tracking.
- Does not show your location.
- Does not store your full medical record.
- Does not automatically update your contact information.
For lost-pet recovery, the number needs to be connected to current owner information in a microchip registry. Travel compliance is separate: border officials and veterinarians use the scanned number to match your dog to the paperwork.
Does the United States Require an ISO Microchip?
CDC does not say that a dog must have a particular brand or an ISO-compliant chip to enter the United States. It says the chip must be detectable with a universal scanner.
That makes ISO compatibility a strong international-travel choice, but not a rule that should be falsely attributed to CDC.
A 15-digit chip designed around ISO 11784 and ISO 11785 standards is often easier to use across countries. Other destinations may require an ISO-compatible chip or make the traveler carry a reader that works with a non-ISO chip.
If your dog needs a new chip, ask the veterinarian for one intended for international travel. If your dog already has a chip:
- Have the veterinarian scan it.
- Confirm the full number.
- Ask whether a universal scanner can read it.
- Check the rules for the origin, transit, and destination countries.
CDC specifically recommends confirming readability if the chip number starts with a number other than 9.
Why Microchip and Rabies Vaccination Order Matters
The safest sequence for a newly chipped travel dog is:
- Implant the microchip.
- Scan it and record the number.
- Give the rabies vaccination that will be used for travel.
- Put that same chip number on the vaccination record and later travel documents.
This sequence prevents problems across routes, but the exact legal reason depends on the pathway.
For a dog entering the US after being in a high-risk country, CDC rabies documentation requires the qualifying rabies vaccination to have been administered after implantation. A foreign-vaccinated dog in this pathway needs a Certification of Foreign Rabies Vaccination and Microchip form. A qualifying US-vaccinated dog needs the applicable USDA-endorsed CDC vaccination documentation.
For a dog coming only from rabies-free or low-risk countries, CDC does not require additional federal rabies documentation. The dog still needs a readable chip and Dog Import Form receipt, but the low-risk CDC pathway does not itself require proof of a chip-before-vaccine sequence.
Do not stop at the CDC rule. Another country on the itinerary may impose a stricter sequence. For example, USDA’s EU guidance requires the chip to be implanted and scanned before the travel-valid rabies vaccination.
Where the Microchip Number Must Match
Treat the microchip number like a passport number. One incorrect digit can make the documents appear to describe a different dog.
Compare the scanned number with every applicable record:
- CDC Dog Import Form
- Rabies vaccination certificate
- Certification of U.S.-Issued Rabies Vaccination
- Certification of Foreign Rabies Vaccination and Microchip
- International health certificate
- Origin-country export certificate
- Rabies antibody test report, when required
- Airline or pet-shipping paperwork
Do not copy the number from memory. Do not rely only on an old sticker in a file. Ask the veterinarian to scan the dog and read the result directly.
Spaces and punctuation may be displayed differently between systems. The underlying sequence of letters or numbers must still match.
What If Your Dog Has 2 Microchips?
CDC’s Dog Import Form instructions say to enter the microchip number that is readable and documented on the official veterinary paperwork accompanying the dog.
If your dog has 2 chips:
- Have the veterinarian scan and record both.
- Identify which number will be used as the primary travel identifier.
- Use that number consistently on the CDC form and supporting records.
- Check whether the origin or transit country requires both numbers on its certificate.
- Never hide the existence of the second chip when a form asks for all identifiers.
USDA’s EU guidance says that when a second ISO-compliant chip is added because an older chip is not ISO compatible, both numbers should appear on the health certificate.
Do not remove a working chip simply to make the paperwork easier. Ask the veterinarian and the relevant government authority how both identifiers should be documented.
What If the Chip Will Not Scan?
Do not wait until airport check-in or arrival inspection to discover a scanning problem.
Ask the veterinarian to scan across the dog’s shoulders, neck, and nearby areas. Chips can move from the original implantation site. If the first scanner does not detect it, the clinic may try another compatible scanner.
If the chip remains unreadable, the veterinarian may recommend implanting another chip. That decision can affect the travel timeline:
- The new number must be added to the documents.
- A destination may require a new rabies vaccination after the new chip is implanted.
- New vaccination or testing waiting periods may apply.
- Existing certificates may need to be replaced.
CDC warns that a dog that has been in a high-risk country may be denied entry and returned to the departure country at the importer’s expense if the chip cannot be scanned on arrival.
CDC does not state that exact consequence for every low-risk arrival on its FAQ page. The correct response is still to fix the problem before travel, not assume an unreadable chip will be accepted.
Registration Is Important, but It Is a Separate Job
Microchip registration connects the identification number to your contact details for lost-pet recovery. It does not replace the CDC Dog Import Form, vaccination records, or a health certificate.
Before moving:
- Find the registry connected to the chip.
- Update your phone number, email address, and future US address when available.
- Add a backup contact who can be reached during the move.
- Save the registry name and account details with your travel records.
- Keep a collar tag on your dog as a second form of identification.
AAHA also recommends having the chip scanned annually to confirm that it still works and can be located.
Pre-Travel Microchip Check
Ask your veterinarian to complete this check before final documents are issued:
- ☐ Scan the dog and confirm the chip works.
- ☐ Confirm it is readable with a universal scanner.
- ☐ Write down the complete number directly from the scan.
- ☐ Compare it with the rabies certificate.
- ☐ Compare it with any titer laboratory report.
- ☐ Use the same number on the CDC Dog Import Form.
- ☐ Use the same number on the health and export certificates.
- ☐ Record both numbers correctly if the dog has 2 chips.
- ☐ Confirm the chip-and-vaccine sequence meets every country’s rules.
- ☐ Update the registry contact information.
Complete this before the final health-certificate appointment. Correcting an identity mismatch after government endorsement may mean issuing and endorsing the document again.
Common Dog Microchip Mistakes
Assuming every US-bound dog needs an ISO chip
CDC requires universal-scanner readability, not a specific brand. ISO compatibility is still a sensible international choice because other countries may require it.
Giving the travel-valid rabies vaccine too early
For pathways that require the chip to precede vaccination, a vaccine given first may not count. The dog may need to be revaccinated and complete a new waiting period.
Copying one digit incorrectly
A typo can disconnect the veterinary records from the dog. Compare each document with a fresh scan.
Never testing the chip before departure
Implantation alone does not prove the chip can still be found and read. Scan it before the final paperwork.
Treating registry enrollment as the travel requirement
Registration helps recover a lost dog. It does not prove compliance with CDC import rules.
Ignoring transit-country rules
A dog can meet the US rule and still fail another country’s microchip standard or vaccination sequence.
