High deductible health plans (HDHPs) have become increasingly common as a means of increasing access to health insurance while curbing total utilization. However, high out-of-pocket (OOP) expenditures faced by HDHP enrollees may disincentivize high value care, particularly for people with chronic but costly health conditions like diabetes. Glucose-lowering drugs are a large part of direct costs of diabetes management and contribute to cost-related non-adherence, burden of treatment, and poor health outcomes. We examined the changes in OOP expenses for a 30-day supply of each class of glucose-lowering drugs among 43,900 adults with diabetes included in OptumLabs® Data Warehouse between 20 and 2018 who switched from non-HDHPs to HDHPs, compared to 333,803 adults who did not switch. The mean OOP expenses, standardized to 20$US, were higher for HDHP beneficiaries (Table) . Switching to a HDHP significantly increased OOP expenditures for all glucose-lowering classes, ranging from 5% increase (sulfonylurea) to 48% increase (glitazone) . This increased expense for patients may hinder adherence and adversely impact glycemic management and health outcomes among HDHP enrollees. Clinicians should be aware that HDHP enrollees may be more sensitive to OOP costs when choosing medications, and policy makers should exempt evidence-based prescription drugs from high deductibles. Disclosure D.H.Jiang: None. J.Herrin: Consultant; Johnson & Johnson Medical Devices Companies. H.Van houten: None. R.G.Mccoy: Consultant; Emmi. Funding National Institute of Diabetes and Digestive and Kidney Diseases grant number K23DK114497
