It is really a very poor customer service issue that they dont post the miles expiration date clearly on the web page. As pointed out above both AA and UA do this very clearly. I got an email a couple weeks ago that my miles were about to expire. To their credit, it was pretty far in advance. I had a shuttle flight coming up anyway. I usually credit those to UA but I didnt need it to qualify as 1K on UA this year so I credited it to my US account. I have about 165K miles so I need to figure out what to do with them. But US should really post this information clearly on the web site. They would have a much better PR case when the miles do expire if they started doing that.