Samsung Pay launches in the US today.

Caution: When using Samsung Pay, the people behind you in line and the clerk at the counter will think you have gone crazy.

Samsung Pay, the mobile payment system from Samsung that I would argue is actually a game changer, launches today in the US. I say that it’s a game changer because it’s not just another NFC payment system that requires retailers to have NFC-ready payment terminals. With Samsung Pay, you can (theoretically) pay at almost every credit card terminal you encounter, because it uses magnetic secure transmission (MST) that emulates a credit card swipe.

Here are the details for today’s launch in the US.

Carrier Support

As of this morning, Samsung Pay works on the Galaxy S6, Galaxy S6 Edge, Galaxy S6 Edge+, and Galaxy Note 5 in the US on AT&T, Sprint, T-Mobile, and US Cellular. Verizon is still “evaluating” Samsung Pay for use.

Credit Card Support

As for which cards Samsung Pay supports, you will need a card issued by Bank of America, Citi, American Express, or US Bank. Samsung has a partnership with MasterCard and Visa, but it’s going through card issuers for individual card support. If you don’t have a card from one of those four I just mentioned, you will have to remain patient.

How it works

To use Samsung Pay, you get the choice of how to pay depending on the situation. If you are at a retailer with NFC-ready terminals, you can pay by tapping your phone to the NFC spot like you would with Android Pay or Apple Pay. If you are at a terminal that doesn’t have an NFC pad, you then press your phone up against the credit card swiping slot and the phone will emulate a card swipe.