I have an upcoming roundtrip CLE-EWR. I need to change my return from Monday to Sunday but they want a $200.00 change fee. If I cancel the return and just book a one-way using FF miles, do I loose my miles on the outbound. On CO it used to be you could cancel the return and have up to one year to reschedule and then pay the change fee. I could do that and just never do the the change. Other option would be do a SDC for $75.00 but seats may not be available and I want to firm my flight now.

Current UA policy (other than the amount of the fee) is the same as sCO. If you cancel your return, you will have the value of the return to use for a year. When you use that value, you will pay a $200 change fee in new money.

Note that the value of the second segment may not be 50% of the round-trip and, depending on the fare paid, may not even be worth the $200 you will eventually have to pay to use it.

You will earn the miles due to you for the segments you actually fly. But, don't book the new one-way FF ticket until you've cancelled the return. UA's software may pickup conflicting bookings and cancel one or both.

Smart not to rely on SDC. EWR-CLE on a Sunday can be a zoo.

Your best route here depends on what you paid for your ticket and what your tolerance is for the new ticket.

Why don't you get the award ticket and time it so that you bought it within 24 hours of when the SDC window opens.

Then you can cancel the award ticket for free w/in 24h and do the $75 SDC