Previously, HCCI analyzed prescription drug spending to understand how many insulin users with employer sponsored insurance (ESI) would be affected by a $35 monthly cap on patient out-of-pocket spending on insulin. Our estimates were based on average monthly out-of-pocket spending on insulin across all insulin products. The Inflation Reduction Act (IRA) recently passed by Congress includes a $35 per month cap on out-of-pocket spending on any covered insulin product for those enrolled in Medicare Part D. A similar cap for ESI enrollees was proposed but ultimately excluded from the final version of the legislation.
As a follow-up to our original brief, we updated our analysis to understand how many people with ESI would be affected by the $35 monthly insulin cap per insulin product included in the IRA. Specifically, we used HCCI’s claims dataset to look at how much people spend on average per 30-day supply of insulin per each insulin product. We weighted our data to be representative of the entire ESI population in the U.S., using HCCUR methodology.
We found that over 50% of insulin users with ESI spent over $35 out-of-pocket on average for a 30-day supply of insulin in 2019 and 2020. Table 1 shows the percentage of people that meet each out-of-pocket spending threshold.
Table 1. Percent of ESI Enrollees that Met each Out-of-Pocket Spending Threshold on 30-day Supply of Insulin
| OOP Spending Threshold | 2019 Percent of ESI Enrollees | 2020 Percent of ESI Enrollees |
| <= $35 | 47.9% | 49.5% |
| $36-50 | 19.9% | 20.1% |
| $51-100 | 19.7% | 18.9% |
| $101-200 | 7.2% | 6.8% |
| > $200 | 5.3% | 4.7% |
Our earlier methodology provided a higher estimate of the percent of insulin users with ESI that would be affected by the $35 insulin cap. Our updated methodology accounts for days supplied per product, rather than averaging total out-of-pocket spending on all insulin per month. This updated methodology results in a lower percent of insulin users who would reach the cap because it excludes (1) people who had two prescriptions that together were >$35 but individually neither was and (2) people who filled a >30-day supply for over $35 in a given month but when you look at the 30-day equivalent cost, it was not >$35.
Methods Note
We calculated monthly out-of-pocket spending on fills for prescriptions of all types of insulin products (pulled from the U.S. Food and Drug Administration National Drug Code Directory) using claims data from the Health Care Cost Institute. In Table 1, our sample included individuals enrolled in employer-sponsored insurance coverage for at least one month during calendar years 2019 or 2020, who were under the age of 65, and filled at least one prescription for insulin during the year. We did not restrict to individuals with type 1 diabetes.
Out-of-pocket spending is the total amount paid by the patient at the point of sale and includes amounts applied to a deductible, as well as any required co-insurance or co-pay. Average out-of-pocket spending per 30-day supply reflects total out-of-pocket spending on all claims filled per member per insulin product (unique NDC) divided by total days supplied for all prescriptions filled for that product.