Originally Posted by
DesertFlier
As an FYI - Delta and AA will only match you up to 50k level, regardless if you are currently a higher status level. CO does match equivalent higher levels, however, but their top tier is Platinum (75k).
Actually, AA generally does not match. It's a Challenge, now with a fee:
http://flyerguide.com/wiki/index.php/Challenge_(AA)
You are correct that only AA Gold (25K equiv) and Platinum (50K equiv) challenges are offered.