Originally Posted by sbm12

AFAIK it is as many as you want (up to the 6 stops) though each counts as a segment against the 16 you're allowed.

Buy a separate ticket. Although UA flies the route as a tag-on I know they cannot sell that as a separate trip and I'm 99% certain that applies to award trips if the agent is paying attention to the rules. I've read scattered reports that suggest it can be used on an award ticket when connecting onward international flight but I'm not sure if that can add a stop along the way or only be used for a connection..