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 Can a Landlord Deny an ESA? How Much Is to Certify a Therapy Dog? How to Get an ESA Letter in New York Is ESA Legitimate? [therapypet_step1_form show_in_mobile="1"]