Short answer
Since January 2021, US airlines don't have to accept emotional support animals, so an ESA flies as a pet under the airline's pet policy and fees. A psychiatric service dog trained to perform disability-related tasks can still fly in the cabin at no charge, using the DOT Service Animal Air Transportation Form.
For years, an ESA letter was often enough to bring an emotional support animal into an airplane cabin without a pet fee. Airlines saw a sharp rise in animals on board, along with incidents and disputes, and the U.S. Department of Transportation changed its rules. Plenty of websites still haven't caught up, which is why this guide starts with the current law.
The 2021 DOT rule in plain English
The Department of Transportation's final rule on traveling by air with service animals took effect on January 11, 2021. Under it:
- A service animal is a dog individually trained to do work or perform tasks for a person with a disability, including a psychiatric disability.
- Emotional support animals are not service animals for air travel. Airlines may treat them as pets.
- Airlines can require passengers with service dogs to submit the DOT Service Animal Air Transportation Form, which covers the dog's health, training and behavior.
- Airlines can limit a passenger to two service dogs and require the dog to fit in the passenger's foot space or lap.
Since the rule took effect, the major U.S. airlines have stopped accepting emotional support animals as anything other than pets.
Your ESA letter still matters. It just matters at home, not at the gate. Under the Fair Housing Act it supports your request to live with your animal and to have pet fees and breed or weight limits waived. Air travel was never part of fair housing law.
How to fly with your ESA as a pet
Flying with an emotional support animal now means following your airline's pet policy. In general:
- Small dogs and cats can usually ride in the cabin in an airline-approved carrier that fits under the seat in front of you.
- A pet fee applies, usually somewhere around $100 to $150 each way on major U.S. airlines.
- Space is limited. Airlines cap the number of pets per flight, so book the animal's spot when you book your seat.
- Larger animals may need to travel as checked or cargo pets, and some airlines don't offer that at all.
- Breed and health rules apply. Some airlines restrict short-nosed breeds, and some routes require a health certificate from your vet.
Policies change, so check the airline's pet page shortly before you book and again before you fly.
When a psychiatric service dog can fly in the cabin
A psychiatric service dog is a dog trained to perform specific tasks related to a mental health disability, such as interrupting a panic attack with deep pressure, waking a handler from nightmares or creating space in a crowd. Under the DOT rule, a trained psychiatric service dog can fly in the cabin with its handler, at no pet fee, as long as the airline's requirements are met.
The key word is trained. Emotional support comes from an animal's presence. A service dog's protection comes from tasks it has been taught. A letter doesn't turn an untrained dog into a service dog. If you think you may qualify, our guide on how to get a psychiatric service dog covers training and qualification step by step.
The DOT Service Animal Air Transportation Form
For a service dog, the airline paperwork is the DOT form, not a letter from a clinician. On it, you attest that your dog is trained, has been vaccinated, and behaves in public. Airlines can ask for it up to 48 hours before your flight if you booked earlier than that. The form itself warns that knowingly false statements can carry federal penalties, so only use it for a dog that is genuinely trained.
For flights of eight hours or more, airlines may also ask for a form confirming that your dog won't need to relieve itself on the flight, or can do so in a sanitary way.
International flights
Rules outside the U.S. vary by country and by airline, and many foreign carriers treat emotional support animals as pets too. Entry rules for animals, such as vaccinations, microchips, import permits and quarantine, apply no matter what kind of animal you travel with. Start planning months ahead for international trips.
Trains, buses and hotels
The same pattern holds on the ground. Trains and bus lines generally accept trained service dogs and treat emotional support animals under their pet policies, if they allow pets at all. Hotels must allow service dogs under the ADA, but they aren't required to accept emotional support animals, and the Fair Housing Act doesn't apply to hotels or short-term vacation rentals.
Which letter do you need?
If your main goal is living with your animal without pet rent or restrictions, an ESA housing letter ($99) is the right document. If you have, or are training, a psychiatric service dog, a PSD letter ($139) documents your disability-related need as a handler, which helps with housing and with your own records. Both come from a clinician licensed in your state who reviews your assessment, and you get a full refund if you're not approved.
Frequently asked questions
Can I still fly with my emotional support animal in the cabin?
Only under the airline's pet policy. Since January 2021, U.S. airlines aren't required to accept emotional support animals, so small ESAs usually fly in an under-seat carrier with a pet fee.
Do I need a PSD letter to fly with a psychiatric service dog?
Airlines use the DOT Service Animal Air Transportation Form rather than a clinician's letter. A PSD letter is still useful for housing and to document your need as a handler, but it doesn't replace the DOT form.
Can my cat fly as an emotional support animal?
No airline is required to treat a cat as an emotional support animal. Cats can fly in the cabin as pets in an approved carrier, subject to the airline's pet fee and limits.
Is it okay to call my ESA a service dog so it can fly?
No. Only a dog trained to perform disability-related tasks is a service dog. The DOT form warns that false statements can carry federal penalties, and many states also penalize misrepresenting a service animal.
Does my ESA letter help at all when I travel?
It helps with housing wherever you live under the Fair Housing Act. It doesn't give access to planes, hotels, stores or restaurants.
Sources
- U.S. Department of Transportation, Traveling by Air With Service Animals, final rule, Federal Register, December 10, 2020
- 14 CFR Part 382, Nondiscrimination on the Basis of Disability in Air Travel (Electronic Code of Federal Regulations)
- ADA Requirements: Service Animals (ADA.gov, U.S. Department of Justice)
- Frequently Asked Questions about Service Animals and the ADA (ADA.gov)
Laws and agency positions change. We last checked this page against these sources on October 24, 2026. It is general information, not legal advice.
Find out whether you qualify for an ESA letter
Answer a few questions and a mental health professional licensed in your state reviews your assessment. If you're approved, your Fair Housing Act letter arrives as a PDF, typically within 24 to 48 hours of your evaluation.* $99 one-time, $25 per additional animal, $79 to renew each year. Full refund if you're not approved.
*Arkansas, California, Iowa, Louisiana and Montana require a 30-day client–provider relationship before a letter can be issued, so the letter issues after day 30.