The prices presented here are the average price of the average insulin prescription for individuals ages 0-64, covered by employer-sponsored insurance (ESI), and having been diagnosed with diabetes (either T1D or T2D). The data set is weighted to be representative of the ESI population at both the state and national levels. Average prices are calculated from the actual amounts paid for insulin prescriptions filled at either in-person or mail-order pharmacies; these may differ from publicly reported wholesale list prices. These allowed amounts do not reflect any discounts, rebates, or coupons, nor would they include insulin bought over-the-counter. The average insulin prescription in our sample averages about a 40-day supply. All metrics represent insurance claims for both brand and generic insulin; however, we found very few claims for generic insulin prescriptions. For more information about the dataset and the price calculation methodology, see the Methodology page on the HCCI website.