Congratulations to you and your son! Although you could call Yale’s Financial Aid office now, you don’t have much leverage (other than the fact that you received $25k less in 2016). I would hold off until your son hears back from his other colleges. Should he receive a better financial aid award from one of Yale’s peer school’s (Princeton, Harvard, Columbia, Cornell, Dartmouth, Brown, UPenn, Amherst, Williams, Georgetown, UChicago, Duke), you’ll be in a better position to call Yale’s financial aid office and see if they would re-exmine your son’s financial aid in light of another school’s better offer. You should be prepared to FAX over the better offer to Yale and let Admissions know Yale is his first choice school, but its difficult for your son to accept the offer when another equally competitive college is giving better financial aid.