Originally Posted by
marcuslai
I called MPC for you as I was also curious about the answer to this question. The agent's answer was yes - your return booking would be charged at the reduced rate, so that the entire booking is at the return trip rate. However you will need to pay a change fee (USD 25 or 1,000 miles) to change your one-way trip to a round trip.
With respect, it is (almost) entirely wrong, at least there is a better way.
Option 1
Call in and book the outbound, telling the agent that you have an inbound 360days+ and they will let you hold the seat without issuing the ticket.
Option 2
Issue one-way AND at the time of issuing tell the agent you have a future return flight. Issue the other one-way in the *same PNR*. Pay miles for two one-way and claim difference back after completion of both the inbound and outbound.
The procedure may be a bit different if it involves partner airline though.