I agree with others that the rule is no longer as simple as 1/60 or number of days since last application - my SO just received a MAC denial at 67 days. They'd been applying with Citi exclusively and I'd slowed them down deliberately to go outside of 1/60 but still got denied. One theory: SO had closed three existing AA cards seven days before applying for the new one. Perhaps the MAC logic considers open and closed cards, like Citi's new bonus rules. Would be interesting to hear if others receiving MACs had recently closed cards.