Nearly 5,000 independent pharmacies have banded together to sue Prime Therapeutics, accusing the pharmacy benefit manager of conspiring with Cigna's Express Scripts to fix prices and squeeze them on reimbursements and fees.

The lawsuit, filed by TRUST LLC—a Virginia company formed in 2023 by the National Community Pharmacists Association—alleges that Prime violated antitrust laws and breached its contracts with participating pharmacies. TRUST represents pharmacies that assigned their claims to the organization.

At the heart of the complaint is a claim that Prime and Express Scripts struck a deal in 2019 to share confidential pricing information, allowing Prime to match Express Scripts' reimbursement rates and fee structure. The pharmacies argue this eliminated normal competition, enabling Prime—which they say lacks Express Scripts' market power on its own—to impose worse payment terms than would exist in a competitive market.

Specifically, the suit alleges the agreement let Prime reduce reimbursement rates paid to pharmacies while increasing various fees, including direct and indirect remuneration fees and transaction fees. The pharmacies contend this is a per se unlawful restraint of trade and a Rule of Reason violation under the Sherman Antitrust Act.

But the legal battle isn't just about the alleged price-fixing. The pharmacies also accuse Prime of using mandatory arbitration clauses to stall their claims. According to the complaint, Prime introduced a mandatory arbitration amendment to its Pharmacy Participation Agreements, effective December 1, 2024, requiring disputes to be resolved before JAMS. TRUST says it complied by filing a demand for arbitration in October 2025 and providing Prime with assignment documentation.

However, Prime allegedly later argued that many pharmacies weren't subject to the JAMS provision and should instead go to the American Arbitration Association (AAA)—without specifying which pharmacies were affected. When TRUST filed with the AAA in April 2026, Prime reportedly indicated it would challenge that forum too. The plaintiffs say Prime has refused to commit to any dispute resolution process, effectively blocking pharmacies from pursuing their claims despite imposing mandatory arbitration.

The lawsuit seeks damages under federal antitrust law and compensation for breach of contract. A copy of the complaint was published online by Bloomberg Law last week.

This case highlights the ongoing tension between independent pharmacies and the powerful pharmacy benefit managers that control drug pricing and access. For retail investors, it's a reminder of the regulatory and legal risks facing companies like Cigna (Cigna (CI)), which owns Express Scripts.