Yup. No expiration if you have a OnePass Plus or MileagePlus Explorer though.
Now, I'm confused, following is a cut out from an AP article today;
"Miles in the combined program will expire after a year and a half. That?s not a change for United travelers. Continental miles had no expiration date, although accounts could become inactive after a year and a half if no new miles were earned."
Here it seems that unlike CO, UA miles will expire regardless of activity/inactivity. Whereas upon reading UA insider's report, it seems otherwise. Following is what Scott had to say;
"Aligned mileage expiration policy. Miles will expire if your account is left inactive for 18 months. Our definition of activity will be very easy to meet for earning or redemption in thousands of ways. This includes something as simple as a magazine subscription redemption ? which can be had for as little as 400 miles."
Makes one wonder, who holds the truth...?