Working Paper: NBER ID: w23342
Authors: Johanna Catherine Maclean; Brendan Saloner
Abstract: We examine Medicaid expansion under the Affordable Care Act (ACA) on substance use disorder (SUD) treatment utilization and financing. We couple administrative data on admissions to specialty SUD treatment and prescriptions for medications used to treat SUDs with a differences-in-differences design, comparing expanding and non-expanding states. Post-expansion, admissions did not significantly change in expanding states relative to non-expanding states. We find that in expanding states Medicaid insurance and use of Medicaid to pay for treatment increased by 13.9 percentage points (71%) and 12.9 percentage points (75%) following the expansion. Post expansion, Medicaid-reimbursed prescriptions for medications used to treat SUDs in outpatient settings increased by 43% in expanding states relative to non-expanding states. We find no statistically significant evidence that Medicaid expansions affected fatal alcohol poisonings or drug-related overdoses. Overall, our findings imply that ACA Medicaid expansion had a large impact on the financing of SUD treatment and medication receipt.
Keywords: Medicaid; Affordable Care Act; substance use disorder; treatment utilization
JEL Codes: I1; I13; I18
Edges that are evidenced by causal inference methods are in orange, and the rest are in light blue.
| Cause | Effect |
|---|---|
| Medicaid expansion (I18) | Medicaid insurance coverage among patients receiving specialty SUD treatment (I18) |
| Medicaid expansion (I18) | use of Medicaid as a payment source (I18) |
| Medicaid expansion (I18) | Medicaid-reimbursed prescriptions for medications used to treat SUDs in outpatient settings (I18) |
| Medicaid expansion (I18) | fatal alcohol poisonings (I12) |
| Medicaid expansion (I18) | drug-related overdoses (I12) |