Association of Medicaid expansion of the Affordable Care Act with operations for benign endocrine surgical disease.

•Background: The Affordable Care Act's Medicaid expansion increased insurance coverage and access to care for endocrine cancers, though impact on benign endocrine disease is unknown. •Methods: Patients undergoing operations for benign thyroid, parathyroid, and adrenal disease were collected from the Vizient® Clinical Data Base from 2009 to 2016 and grouped by state Medicaid expansion status in January 2014. Insurance coverage was analyzed by difference-in-differences analysis, and logistic regression evaluated odds of operation by insurance status. •Results: 134,242 patients were included. Medicaid coverage in expansion states increased for all operations (Adj-DD 5.78%, p < 0.001) with decreases in uninsured and private insurance. Medicaid patients had increased odds of undergoing thyroid operations (OR 1.56, p < 0.001) and decreased odds of parathyroid (OR 0.68, p < 0.001) or adrenal operations (OR 0.70, p < 0.001) versus private insurance. •Conclusion: Medicaid expansion increased insurance coverage for benign endocrine disease, however, barriers remain for Medicaid patients with parathyroid and adrenal disease.