What is American Airlines policy if they change your flight?

If your flight get’s changed by the airline, you’ll book the next available flight toward the destination. The basic motive is to make the situation more convenient for travelers. 

What are the important points about changing flights with American Airlines?

There are some points to read below:

1. You don’t need to pay the fee for the domestic followed by the short & long-haul international. But, it’s till you are not flying in the basic economy. 
2. However, the basic economy fares are non-refundable & can not be changed.
3. It also includes flying on a stand-by flight if you are flying to the same destination on the same day. 

These are the points about American Airlines Flight Change policy for more details.