What is known? In most states, Medicaid waivers provide individuals with an intellectual disability diagnosis generous healthcare coverage throughout adulthood. By comparison, fewer Medicaid programs are available for autistic individuals, and they are more likely to experience disruptions, or gaps, in Medicaid coverage and subsequently not re-enroll.
What this paper adds? One in five autistic individuals with Medicaid coverage between ages 8 and 25 accrued a new intellectual disability diagnosis. The probability of a new intellectual disability diagnosis was higher among those who had previous disruptions in Medicaid coverage.
Implications for research and policy. Expanding Medicaid to cover autistic people of all ages could decrease the need for intellectual disability diagnosis accrual. Input from autistic individuals and their families regarding their health insurance access and healthcare experiences is critically important to understanding next steps for research.
One possibility is that they did not need ID services earlier, or simply fell through the cracks.
The second explanation is that individuals in our sample were diagnosed with ID as a mechanism for retaining or regaining Medicaid coverage not afforded to individuals with ASD alone. Prior research by Shea and colleagues (2022) supports this hypothesis; they observed autistic Medicaid enrollees with ID had half the probability of Medicaid disenrollment compared to those with ASD alone. Given individuals with ID have frequent interactions with the healthcare system (Shea et al., 2018), we expect our eligibility criteria of least 1 + claim in a 12-month period to be appropriate for identifying ID; sensitivity analyses supported robustness of these findings. Because of their established advocacy history people with ID are often more likely to be Medicaid-eligible than autistic people (Rizzolo et al., 2013). While the addition of an ID diagnosis among autistic people may help maintain Medicaid enrollment, it also could lead to autistic individuals not receiving autism-specific or appropriate healthcare if access is limited to ID-specific services (Shea et al., 2021). Although outpatient behavioral health services are the typical intervention modality recommended for both ASD and ID (Lloyd & Kennedy, 2014), the cognitive deficits observed in ID differ from the social and communication challenges observed in ASD (American Psychiatric Association, 2013).
