Will Tmobile Iphone 5s Work With Other GSM Carriers Sim Card?

I'm using Tmobile phone number, and I just get an Iphone 5s today from Tmobile, not from Apple.
I wonder whether I can use this Iphone 5s with other GSM sim card? If not, do you know where I can find a unlock service for Tmobile Iphone 5?

First off t-mobile has one I phones which only work for AT&T, metro pcs, and tmobile. My best guess is to go to "ubreakifix" they do unlocks and everything else and return your phone within the same day. Or you can factory unlock it and it costs more than your local "ubreakifix" but I don't know if t-mobile has it. Also since the 5s is brand new I don't know if anyone will have the unlock software, so I recommend calling before you go.