What is the cancellation policy with American Airlines?

You have 24 hours from the time you first buy your ticket to make changes or cancel for a refund if you booked at least 2 days before departure 1-844 AA (949-8748). After 24 hours, refunds are not allowed for non-refundable fares. You can change or cancel your trip online in just a few steps.

Source: https://support.google.com/voice/thread/306432543