What carriers take CMDA iPhones?

I have an iPhone 4 that was connected to the sprint network. I just bought it and I'm not with Sprint anymore, I bought it off Craigslist (if that helps) and I really do not have the money to dish out a contract AND a phone. CMDA meaning no SIM slot.

Verizon uses CDMA.

CDMA iphone has a sim slot, unless it's the first verizon iPhone. However, if the phone is locked, then you can't use it in the US even if it has a slot 'cause verizon locks the GSM slot within the US. Last time I remember, Sprint did not lock the GSM slot. Look for a tiny pinhole on the side or top and take it to an AT&T (GSM) or Verizon CDMA and see.

CDMA not CMDA.

Fairly limited there.

Verizon
Cricket
Boost Mobile
US Cellular
metroPCS

ones I know off hand.

Kajeet prepaid will allow you to bring your old Sprint phone to them. Kajeet is a prepaid company for kids. But the rates are pretty reasonable.