As it is clearly stated in the specs, every Nexus 5 sold in North-America(Model No: D820), is both CDMA & GSM Capable. Although it can't be used on Verizon. The rest of the world edition(Model No: D821) is GSM only.
Rajan Ji, Nexus 5 that is being sold on Google Play store(US) is also a CDMA capable, in fact Sprint has confirmed to AndroidCentral.com that any Nexus 5 that is bought on Google Play store(US) can be brought to them and they will activate the same.
NOTE: On a side note, my Nexus 5 is on its way from Lousiville, KY(UPS hub that is being used as the center for all the shipments of Nexus 5 in US) to my shipping forward service hub. I may have it in hand 10 days from now :dance: .