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 Do You Need a Prescription for a Service Dog? Can a Landlord Deny an Emotional Support Animal? How Long After an ESA Medical Assessment Do I Get a Letter? [therapypet_step1_form show_in_mobile="1"]