Can you put a T-Mobile SIM card into an iPhone 5?

So i have a really crappy flip phone and i really want an iPhone, I'm currently saving up for one. But I'm not sure if you can put a T-mobile Sim card into an iPhone. No no no, I don't want to cut the Sim card, I'm not taking that risk. Can I buy one from the T-mobile store? If so, what am I supposed to ask for? And will all my contacts/data be on the Sim card when i buy a new one?

You are aware that T-Mobile sells the iPhone 5 now right? You could buy it from them, have your SIM information transfered, since its either that or it must be cut in order to fit in the 5's nanoSIM tray & they would do whatever necessary.