Yes it does, the maps are not actually stored on your iPhone but are streamed to your iPhone during use. To cut down on your data usage, you may want to download one of the many GPS navigation apps that allows you to download maps for offline use. I use Navigon, myself. It's not cheap, almost $50.00, which includes a full North America map set. To save on storage space, you can only download those maps you will need for your trip.I have the 5S. If I am not in a WiFi area, does Apple's pre-installed Maps app use data? I will be driving from LA to San Diego. Thanks, cb