Originally Posted by
Majuki
You use your passport or green card to enter at airports. The only use for the GE card would be by cross by land back into the US if you want to use the Nexus or SENTRI lanes. It cannot be used heading into another country though. It's also good as a second ID or to confuse the TSA travel document checkers at airports. It's handy too because it doesn't contain your home address like a driver's license or evidence of travel history like a passport book.
Couple of points. It can be activated for use of Nexus going to Canada, but that requires having an interview with CBP in Canada and submitting an application. As for coming back from Mexico, if you want to drive a vehicle through the SENTRI lanes you must have the vehicle inspected by US Customs at a SENTRI enrollment center. Otherwise the card just allows you to enter via the pedestrian SENTRI lanes.
Also the card will work for any sea entry or rail entry.
The only time I carry it though is when I go to Australia. They allow US citizens enrolled in GE to use the entry gates for immigration just like their citizens. However if you have problems getting the gate to recognize you I've found it's best to have proof of GE enrollment.