United Airlines has announced a 20 percent off sale on “saver” award tickets to Mexico City. Tickets must be purchased by April 29, 2014, for travel in May 2014.
Roundtrip saver awards between the U.S. (excluding Hawaii and Guam) or Canada and Mexico City, Mexico normally cost 35,000 miles. For the month of May 2014, the price is 28,000 Mileage Plus miles, plus taxes and fees.
There was plenty of saver award availability when I checked flights from and to IAD.
Here’s the link to the full terms and conditions.