This integrative review explores the barriers to and facilitators of healthcare access in adults with intellectual and developmental disorders (IDD) and communication difficulties (CD) using Levesque et al.'s conceptual framework of access to health. IDDs are a group of disorders that occur early in childhood and often involve language dysfunction. CDs are prevalent in adults with IDD. Several themes emerged as barriers to access for adults with IDDs and CDs including health literacy, understanding health information, and screening; fear and negative patient expectations; impaired autonomy; time; accommodation needs; insurance coverage and financial hardship; communication; coordination and continuity of care; and supporter presence and inclusion. Communication between providers, patients, and supporters is a significant barrier for adults with IDD and CD.