How UnitedHealthcare’s 2025 formulary exclusions of insulin biosimilars could drive mid-year cost adjustments in self-funded employer plans
What change is UnitedHealthcare making in 2025?
Starting January 1, 2025, UnitedHealthcare (UHC) will remove several insulin biosimilars from its standard commercial formularies. Internal plan materials show that Semglee (insulin glargine-yfgn, Viatris/Biocon) and Rezvoglar (insulin glargine-aglr, Eli Lilly) will be dropped in favor of Lantus (insulin glargine, Sanofi). Until now, those biosimilars sat comfortably on Tier 2 while Lantus was on Tier 3 or carried higher coinsurance. The change points to UHC backing a preferred brand contract rather than sticking with lowest-net-cost strategies that had supported biosimilar adoption.
Who is affected?
The exclusions reach both fully insured and ASO (administrative services only) commercial groups that use UHC’s standard formulary setups. Self-funded employers with customized drug lists or carved-out PBM models might see ripple effects once claims start processing under the new terms. Pharmacists working under OptumRx will need to adjust their dispensing systems so prescriptions route toward the newly preferred insulin.
Why it matters for self-funded employer plans
Self-funded employers track expected pharmacy costs down to the decimal when setting budgets. A formulary reshuffle that nudges use back toward higher-cost brands blows up those projections fast. CMS data show average sales price gaps of more than 15% per unit between Lantus and Semglee in 2024. Even a modest shift, say a fifth of users moving back to Lantus, can swing total spend by serious dollars.
During mid-year reviews, most employers expect to see biosimilar savings starting to materialize. Flip that upside down, and they’ll find cost surprises unless they revisit stop-loss targets or renegotiate rebate arrangements. Not a fun conversation with finance.
How formulary exclusions can alter cost assumptions
| Product | Manufacturer | Formulary Status (2024) | Formulary Status (2025) | Typical Net Cost Impact |
|---|---|---|---|---|
| Semglee (insulin glargine-yfgn) | Viatris/Biocon | Preferred Tier 2 | Excluded | +15% vs 2024 baseline |
| Rezvoglar (insulin glargine-aglr) | Eli Lilly | Preferred Tier 2 | Excluded | +12% vs 2024 baseline |
| Lantus (insulin glargine) | Sanofi | Non-preferred Tier 3 | Preferred | Net rebate offset uncertain |
Consultant models suggest that if even half of self-funded groups mirror UHC’s preferred list, their total insulin costs could rise 5-8% next year. That projection assumes everything else holds steady, utilization, adherence, refill rates. Real life rarely cooperates, though, so mid-year plan tweaks to member cost-sharing or employer contributions are likely on the table once claims data roll in.
What plan sponsors and pharmacists can do now
Employers first need to check whether they automatically inherit UHC’s standard formulary or maintain their own drug list. If it’s the former, start reviewing January and February claims immediately. Some groups are commissioning rebate audits to see if the new brand contracts actually offset lost biosimilar savings. Pharmacists, meanwhile, should warn prescribers early about which substitutions will trigger rejections. Better to prevent a refill scramble than to fix it later.
Patients switching to a preferred branded insulin will notice the difference at the register. Members with flat dollar copays might not care, but anyone paying percentage coinsurance will. Clear communication beats angry phone calls, something every plan administrator learns the hard way.
Will other payers follow?
Not yet. CVS Caremark and Express Scripts still lean toward biosimilar access for most glargine versions, though future rebate negotiations could change that. KFF’s review of 2024 employer plans showed that over 70% still preferred biosimilars. Whether UHC’s move sparks a broader shift depends on how large employers respond once their 2025 costs come in. Personally, I’ll be surprised if everyone else jumps right away, rebate math tends to have regional logic to it.
Disclaimer: This article offers general information for educational purposes only. It isn’t financial, medical, or legal advice. Plan terms vary. Always confirm details with your pharmacy benefit manager, plan administrator, or licensed pharmacist before making changes.