Microchip rules for dogs entering the U.S. (is ISO required?)
The rule
Every dog entering the U.S. must have a microchip that can be detected with a universal scanner. (CDC: Entry Requirements for Dogs from Dog-Rabies Free or Low-Risk Countries)
- Any brand is fine. CDC does not name ISO 11784/11785 as a requirement; the test is whether a universal scanner can read it. CDC suggests checking with your vet if the number does not start with 9. (CDC: Frequently Asked Questions on Dog Importations)
- For dogs from high-risk countries, the chip must be implanted before the rabies vaccine, or the vaccine is invalid. (CDC: Entry Requirements for Foreign-Vaccinated Dogs from High-Risk Countries)
- The microchip number must appear on all required documents for high-risk dogs, including the CDC Dog Import Form. If a dog has more than one chip, use the readable one that is on the vet paperwork. (CDC: Dog Import Form and Instructions)
What happens if it can't be read
If the chip can't be scanned on arrival for a dog that has been in a high-risk country, the dog may be denied entry and returned at the importer's expense. (CDC: Frequently Asked Questions on Dog Importations)
Practical tips
- Ask your vet to scan the chip at the pre-travel visit and compare the number with every document.
- Watch for typos: one wrong digit is a mismatch.
Note: Airlines and other countries (for the outbound trip) may have their own microchip standards, often ISO. Check those separately; this page covers U.S. CDC entry only.
Sources
- CDC: Entry Requirements for Dogs from Dog-Rabies Free or Low-Risk Countries
- CDC: Frequently Asked Questions on Dog Importations
- CDC: Entry Requirements for Foreign-Vaccinated Dogs from High-Risk Countries
- CDC: Dog Import Form and Instructions
More guides
- Airline and CDC timing: a countdown for flying your dog into the U.S.
- CDC Dog Import Form: step-by-step guide (2026)
- Bringing a dog from Colombia to the U.S. (CDC high-risk rules)
- Common reasons dogs are denied entry to the U.S. (and how to avoid them)
- CDC high-risk countries for dog rabies: the list explained
- Bringing a dog from Mexico to the U.S. (CDC rules for 2026)
- Bringing a dog from the Philippines to the U.S. (CDC high-risk rules)
- Rabies vaccine, titer and certificate rules for dogs entering the U.S.
- U.S. dog entry requirements by risk category (comparison table)
- Returning to the U.S. with your U.S.-vaccinated dog from a high-risk country
- Bringing a dog from Thailand to the U.S. (CDC high-risk rules)