How Cigna’s 2025 mid-year formulary updates for migraine biologics reflect new PBM rebate structures and employer cost-sharing strategies

Cigna’s 2025 Mid-Year Formulary Shake-Up for Migraine Biologics: A Look Through the PBM and Employer Lens

So what exactly is changing?

Starting July 1, 2025, Cigna is revising coverage for several calcitonin gene-related peptide (CGRP) inhibitor biologics used in migraine prevention. The key changes involve tier shifts and preferred product status for three big names: Aimovig (erenumab, Amgen), Emgality (galcanezumab, Eli Lilly), and Ajovy (fremanezumab, Teva). Aimovig will drop from the preferred specialty tier (Tier 3) to nonpreferred (Tier 4). Emgality becomes the only preferred CGRP monoclonal antibody across most of Cigna’s commercial formularies. Ajovy stays nonpreferred but covered with prior authorization. These adjustments hit both employer-sponsored and individual plans under Cigna Pharmacy Management.

This is a mid-year update, rare timing, so it probably isn’t about new clinical data. It’s about the money flows under new contract terms.

Why make this change now?

Mid-year formulary moves usually point to behind-the-scenes rebate renegotiations. Express Scripts, Cigna’s PBM, has refreshed rebate contracts with manufacturers for 2025. Those contracts often include “rebate guarantees,” meaning the PBM owes employers a set rebate per claim. When a drug maker offers richer rebate terms, the PBM shifts the formulary to keep those guarantees intact. It’s a game of economics, not efficacy.

Employers that use Cigna’s pharmacy benefits will see this in their rebate accounting. List prices for all CGRP inhibitors sit around $690 per monthly autoinjector per FDA data, but the net cost after rebates swings widely. By changing which brand gets preferred status, PBMs protect rebate guarantees and deliver on savings targets negotiated months earlier.

What happens to patients’ out-of-pocket costs?

Aimovig users who stay put will probably pay more after July 1. Tier 3 specialty drugs often carry around 25% coinsurance, while Tier 4 can land closer to 40%, depending on the employer design. Emgality users, on the other hand, may see their monthly bills dip once it becomes preferred. Simple as that, even though few patients find it simple.

Here’s how it looks if you map it to Cigna’s 2024 National Formulary structure as a baseline comparison:

Connecting the dots to PBM rebate transparency

The Centers for Medicare & Medicaid Services (CMS) and the Department of Health and Human Services (HHS) have pushed PBMs toward more transparency in rebate practices. The 2023 CMS rule on “manufacturer rebates at point of sale” nudged employer plans to reflect actual net prices instead of opaque list prices minus mystery discounts. PBMs, facing pressure, are tightening formularies to keep rebate revenue predictable while honoring these new rules.

With one preferred CGRP biologic, Cigna’s PBM arm (Express Scripts) can simplify rebate handling. It’s leaner to manage one main contract with deeper discounts and to apply the same prior authorization logic planwide. Employers like it because rebate returns look reliable on paper. Pharmacists and patients? They deal with the operational hassle that follows every formulary reshuffle, new authorizations, new copay cards, more calls.

What this means for self-funded employers

Large employers using Cigna’s PBM are mostly self-funded, they pay claim costs themselves; Cigna just moves the money and runs the system. Data from the KFF 2024 Employer Health Benefits Survey shows about 65% of covered workers fall into self-funded plans. For these employers, this isn’t just a formulary shift but a change in “net effective pricing.” Keep Aimovig on coverage, and rebates may still come in, but unless the contract is 100% pass-through, the PBM pockets more of the margin.

Some employers are getting wise to that and bring in independent PBM auditors or carve out specialty pharmacy management altogether. Cigna’s employer updates hint that rebate guarantees for specialty categories will run roughly 15-20% higher than in 2024, depending on drug mix and utilization. It’s clear what’s happening here: formulary management is being used as a financial lever in real time.

From a pharmacy operations standpoint

Beginning July 1, pharmacies will see claim rejections for Aimovig listed as “nonpreferred.” Expect short-term transition fills, typically 30 to 60 days. Emgality will still require step therapy, meaning the patient needs documentation of prior triptan or gepant use. Pharmacists will have to stay alert, help patients navigate prior authorizations, cost exposure, and whether manufacturer savings cards remain valid. Patients should double-check their specialty pharmacy’s network status too, since some independents can lose contracts mid-year. It happens fast.

And look, having worked with employers through enough of these midyear bulletins, the real story isn’t just formulary tiers. It’s the constant balancing act between rebate math and member experience. Nobody loves these changes, not even the plan sponsors, but they do love hitting their rebate guarantees.

Bottom line

This 2025 update from Cigna shows how PBMs fine-tune formularies to maintain rebate value and keep employer cost-sharing targets on pace. Employers get the predictable rebates they want. Patients experience the tier shifts and authorizations in real life. Pharmacists adjust on the fly. A narrow set of migraine drugs just became a case study in midyear rebate economics, and that’s where the story really sits.

Disclaimer: This article is for informational purposes only and does not constitute medical, legal, or insurance advice. Patients should review plan documents or talk with their healthcare provider for individual coverage details.