uses CDMA and most others use GSM type phones. Straight Talk is a government help program that works similar to TracFone and maybe isn't any cheaper than TracFone either. Some phones do CDMA and GSM both.
http://www.pcmag.com/article2/0,2817,2407896,00.asp
http://www.techradar.com/us/news/phone-and-communications/mobile-phones/verizon-cdma-explained-1189551
Unlocked Vs. Locked Phones
Can my Verizon / Alltel / Sprint / Nextel phone be unlocked?
No, sorry... All the carriers mentioned above operate on CDMA networks and therefore can not be unlocked. Keep in mind that only GSM phones can be unlocked. Some CDMA phones are now dual compatible with GSM Sim cards in order to be used internationally, but for the most part CDMA phones can not be unlocked.
find the right phone for StraightTalk.
http://www.walmart.com/tp/straight-talk-verizon-phones
Looking for a phone that will work on Straight Talk using the Verizon network towers since my area only gets Verizon service. I looked at Samsung Note 4 at a Verizon store but not sure if it will work with Straight Talk. How can I get that or a similar phone and be sure it will use the Verizon towers through Straight Talk? Thanks for your help!

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