In 2026, the answer for Emotional Support Animals (ESAs) on U.S. domestic flights is yes, you almost certainly have to pay. Following the 2021 DOT rule change that allowed airlines to reclassify ESAs as "pets," major carriers like Delta, United, and American no longer recognize ESAs as service animals. This means your ESA is now subject to the standard "Pet in Cabin" fee, which typically ranges from $95 to $150 per flight in 2026. Your animal must also fit within a TSA-approved carrier under the seat in front of you. Only "Task-Trained" Service Animals (like guide dogs for the blind or medical alert dogs) are exempt from these fees and allowed to fly outside of a carrier on the floor. If you are flying in 2026, you must notify the airline in advance and pay the pet fee during the check-in process; failing to do so may result in being denied boarding or having to check the animal as cargo at a significantly higher cost.