This brochure, which is a supplement to the Document “Update on the programmes for the early detection of infant hearing loss: CODEPEH 2019 recommendations (Diagnosis, Treatment and Follow-up)”, completes the review and update of programmes for the early detection of infant hearing loss. It focuses on the diagnosis phase, decision-making regarding treatment, and the follow-up process. Included are updated points related to aetiological and audiological diagnosis, children’s adaptation to prosthetics, early intervention and support for families, and the procedure for case monitoring.