Impact of Medicaid Managed Care on Illinois's Acute Health Services Expenditures for Adults With Intellectual and Developmental Disabilities.

Yamaki et al. (2018) asked a simple question. Does switching adults with IDD to Medicaid Managed Care save money?

They looked at Illinois records before and after the switch. The adults lived in the community, not institutions.

The team compared acute-care costs under the old fee-for-service plan and the new managed-care plan.

The switch did not cut Medicaid spending. Costs stayed about the same.

In short, the hoped-for savings never showed up for this group.

Chezan et al. (2019) looked at the same Illinois system. They found only half of adults with IDD take blood pressure meds as prescribed. Together the papers show managed care is not fixing key service gaps.

Heald et al. (2020) tracked psychotropic use in Australian community services. Prescribing rose over 16 years. Kiyoshi’s U.S. cost data and M’s Australian drug data both warn that community services are under pressure.

Silverman et al. (1994) used the same quasi-experimental design with adults with ID in Britain. Both studies kept tight methods yet found no big effect—Kiyoshi on cost, K on movement disorders—showing null results can be meaningful.

If you write behavior plans for adults with IDD, expect flat Medicaid budgets. Managed care did not free up extra money for extra therapy hours. You may need to justify each hour just as hard as before. Use the solid data from Kiyoshi et al. when you argue for continued funding.