A report I see:
The Boeing 737 Max will fly paying passengers in the US for the first time in 21 months next week as American Airlines is set to fly the first scheduled flight from Miami to New York on December 29.
Flyers can tell if they're on a Max by looking at markings on the plane, the size of the engines and other identifying features.
A passenger's reservation details will also say which aircraft they're booked on and US airlines will let passengers change their flights free of charge if they don't want to fly on a Max.