Establishing care with primary care and specialist clinicians is critical for Medicare beneficiaries with complex care needs. However, beneficiaries with disabilities may struggle to access ambulatory care. This study uses the 2015–17 national Medicare Current Beneficiary Survey linked to claims and administrative data to explore these questions. Medicare beneficiaries (ages 21–64) with disabilities were 119 percent more likely to report difficulty accessing care and were 33 percent and 49 percent more likely to lack annual clinician evaluation and management visits for primary and specialty care, respectively, than those without disabilities. Beneficiaries (ages 21–64) with disabilities also had 42 percent, 67 percent, and 77 percent higher likelihood of having all-cause, nonemergent, and preventable emergency department (ED) visits. Furthermore, people with both a disability and a lack of specialist evaluation and management visits also had 21 percent, 48 percent, and 64 percent increased likelihood of all-cause, nonemergent, and preventable ED visits. Barriers to accessing ambulatory care may be a key contributor to the reliance of Americans with disabilities on ED services.