No but you can try calling to change the flight once you have flown the outbound, I would say 70 percent of the time I have success here with the fare difference being under 100, often it means taking the ba flight rather than aa flight to Bos , the one caveat being I have never had a ticket with Bos as my final destination I am usually trying to change a jfk ticket to Bos, I have literally called twice five minutes apart and gone from a cost difference of 1000, to 30, I always have some sort of j ticket