American Airlines issued this statement on December 9, 2017:
American Airlines customers can now enjoy an improved experience at New York’s LaGuardia Airport (LGA). Beginning on December 9, 2017 all American flights are operating out of Terminal B. This consolidated operation means all customers will check in at Terminal B, and American will operate flights from each of the terminal’s four concourses.
To ensure smooth travels for customers, American’s customer assistance representatives will be stationed throughout Terminal B, as well as in American’s previous space in Terminal C, to guide customers and answer questions.
Map: American Airlines.