Like AT&T before it, Verizon has now secured the necessary waiver from the FCC to roll out Wi-Fi calling. The waiver allows Verizon to delay implementation of teletypewriter (TTY), a service for those with hearing impairments that doesn't work well with Wi-Fi calling. The waiver expires on December 31, 2017, which gives Verizon time to implement its own planned real-time text (RTT) service instead.
It's unclear when we'll see Verizon roll out Wi-Fi calling, but the waiver is the same as the one that was granted to AT&T, which rolled out Wi-Fi calling in a matter of days after it was granted.
To recap, Wi-Fi calling allows customers to place phone calls over Wi-Fi with a compatible phone if they're in a place with limited cellular signal. Calls will then transition between Wi-Fi and cellular when necessary.
Thanks to Keith for the tip!