Ting is an incredibly popular MVNO carrier, where customers are billed only for the calls, texts, and data they actually use (similar to Google Fi and Xfinity Mobile). The carrier already allowed customers to use either GSM or CDMA SIM cards, even across different lines on the same account, and now there's an additional CDMA option.
Ting's GSM support relied on T-Mobile's network, while the CDMA cards used Sprint. Ting announced last year that it would drop the T-Mobile option, and instead partner with Verizon to offer a second CDMA network to Ting customers. The carrier later decided not to drop T-Mobile support, but still promised that Verizon would be an option sometime in 2020. Sure enough, Verizon-backed SIMs (nicknamed 'V1' cards) are now available to customers.
Ting wrote in a blog post, "offering service on three of the four national networks, including the nation’s largest, most reliable 4G LTE network, should set minds at ease that with Ting Mobile, coverage is a given."
It's worth noting that the V1 SIM only works on devices certified for Verizon's network, like Pixels, some OnePlus phones, the Galaxy S/Note series, and most Motorola devices. Ting has a handy checking tool that can tell you if your phone is compatible, though it doesn't tell you specifically which networks will work.
- Ting Blog