TracFone for over a month, but TracFone has never officially acknowledged it. That's finally changed. Yesterday a new "Now you can bring your 4G LTE smartfone to Tracfone" banner started appearing on TracFone's BYOP (Bring Your Own Phone) page.
The BYOP page also has a link to buy a CDMA LTE Activation kit for 99¢. According to ad copy on the site the kit is "Compatible with most 4G LTE and 3G CDMA Phones. An Airtime Service Plan is required for activation. Kit includes: Nano, Micro and Standard CDMA LTE SIMs." Shipping is $4.95. Add a $39.99 airtime card to qualify for free shipping
I believe that TracFone CDMA BYOP has the same limitations as other Verizon MVNO's: no non-Verizon phones and no Verizon Prepaid phones unless they have been used on Verizon Prepaid for at least six months. In addition, the TracFone BYOP page says that BlackBerrys are not allowed.
Don't expect blazing fast LTE speeds either. Users have reported typical Verizon MVNO LTE speeds of 5 Mbps or less.
It Looks Like You Can Now Use Your Own Verizon LTE Phones on TracFone
TracFone LTE Proves Elusive For Early Adopters
Prepaid Operator Profile: TracFone