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 Mast Cell Tumor: Dogs Diet and Nutrition Guide How to Get an ESA Letter in California How Do I Say Sorry to My Dog? Is an ESA a Therapy Dog? [therapypet_step1_form show_in_mobile="1"]