How Long Does ESA Last? March 11th, 2021 Each ESA letter is valid for 12 months after you obtain them from a certified health professional. After one year, you will have to renew your support animal letter. Related Posts Dog Breed DNA Tests: Which Tests Are Best? What is the Best Pet for Beginners? What is the Cleanest Pet to Own? Who is Eligible to Write an ESA Letter? [therapypet_step1_form show_in_mobile="1"]