How do you forward voicemails on iPhone 5 using Verizon

Dial into your voicemail directly (*86). It is (or at least used to be) one of the options you got at the end of listening to the voicemail. You can only forward to other Verizon mobile numbers.

Sorry, turns out the feature is not available with the iPhone's Visual Voice Mail.

http://support.verizonwireless.com/information/voicemail_comparison.html