The HD Voice feature in Verizon 4G LTE coverage area allows up to 6 parties but each call must be initiated by call originator.
From a Home screen, tap Phone (located at the bottom).
From the Dial tab, enter a 10-digit number then tap Phone. To place a call from the Contacts list, tap the Contacts tab, then tap the appropriate number from the corresponding contact.
Once the call has connected, tap Menu (located at the top right).
From the Dial tab, enter a 10-digit number then tap Phone.
Once the call has connected, tap Merge (located at the top).