As the world opens up to vaccinated Americans, the good news is that you can now travel to most of these destinations without the need to quarantine. You may still be tested upon entry, and U.S. rules still require you to be tested within 72 hours of your return to America.

But a number of countries are now adding an extra wrinkle to the requirements for entry.

Switzerland, for example, says that vaccinated Americans can come but only if you’ve had your shots within the last six months.

So if you got your vaccine back in January, you won’t be allowed in Switzerland if you want to go in August.

A good idea is to check with your destination country to determine if it has a similar rule.