<b>State Insulin Out-of-Pocket Cap Policies and Estimated Eligible Populations in the United States, 2019–2026</b>

<jats:p>&lt;p dir="ltr"&gt;&lt;b&gt;Objective&lt;/b&gt;. High insulin prices are a major barrier to diabetes management in the U.S. Since 2019, several states have implemented legislation to mitigate high out-of-pocket (OOP) costs for commercially insured individuals by setting OOP caps. In this study, we examine the reach of these policies.&lt;/p&gt;&lt;p dir="ltr"&gt;&lt;b&gt;Research Design and Methods&lt;/b&gt;. We identified insulin OOP cap legislation enacted through 2026 for each state and Washington DC. Using public data on diabetes prevalence and health insurance, we identified the population eligible and exposed to OOP caps legislation: adults 18-64 years with diabetes, using insulin, enrolled in state-regulated commercial plans, residing in states that enacted OOP caps legislation. We then estimated the number of commercially insured individuals left unprotected due to 1) enrolled in federally-regulated plans, regardless of state of residence; or 2) enrolled in a state-regulated plan but living in a state without OOP cap legislation.&lt;/p&gt;&lt;p dir="ltr"&gt;&lt;b&gt;Results&lt;/b&gt;. By 2026, 29 states and Washington DC had enacted OOP caps on insulin, covering an estimated 1.04 million individuals with diabetes, using insulin, and enrolled in state-regulated commercial plans. Despite these gains, policy reach remains uneven: 0.67 million individuals with state-regulated plans live in states without an insulin OOP cap, and 2.2 million individuals are insured by federally-regulated commercial plans that fall outside of state jurisdiction.&lt;/p&gt;&lt;p dir="ltr"&gt;&lt;b&gt;Conclusions&lt;/b&gt;. State OOP caps have the potential to reduce OOP insulin costs for many commercial plan enrollees, but have limited reach. Legislative efforts to contain costs at the federal level are therefore needed to decrease the financial burden of insulin.&lt;/p&gt;</jats:p>