Simpson Thacher & Bartlett remains a formidable disputes firm, combining elite New York courtroom capability with substantial depth in Washington, D.C., California and Boston. Its practice spans commercial, securities, insurance, antitrust, white-collar, intellectual-property and transactional litigation, with particularly strong results where litigation intersects with major corporate transactions or regulatory intervention.

The firm’s antitrust team delivered one of its clearest recent statements of strength in the public case United States et al. v. UnitedHealth Group et al. Acting for Amedisys, Simpson Thacher helped resolve the government challenge to its $3.3 billion acquisition by UnitedHealth Group. The settlement, filed in federal court and involving the divestiture of 164 home-health and hospice locations across 19 states, enabled the transaction to close. Washington, D.C. partners Sara Razi, Lindsey Bohl, Abram Ellis, Karen Kazmerzak and Preston Miller led the matter, demonstrating the office’s ability to combine merger litigation, negotiation and regulatory strategy.
Public injunction proceedings provide further evidence of the practice’s range. In Frontdoor, Inc. v. Kluver, the firm secured a preliminary injunction enforcing a nationwide non-compete in expedited federal proceedings. It also defeated attempts to enjoin transactions involving Radius Recycling’s $1.34 billion acquisition by Toyota Tsusho America and Silver Lake’s acquisition of Zuora. In antitrust, the firm helped Mattress Firm defeat the FTC’s request for a preliminary injunction against its acquisition by Tempur Sealy.

Insurance remains another defining strength. The firm represented Travelers in the public Red River Talc bankruptcy confirmation trial, involving more than $9 billion in proposed trust funding, and represented Berkshire entities in proceedings concerning approval of a $535 million settlement addressing Whittaker, Clark & Daniels’ talc liabilities. New York partners Lynn Neuner, Bryce Friedman and Michael Garvey are prominent figures in this area; Neuner and Friedman also bring substantial trial credentials to the broader commercial practice.
The firm’s New York bench is anchored by global litigation co-chairs Lynn Neuner and Jonathan Youngwood. Neuner is a versatile trial lawyer across commercial, insurance, securities and advertising disputes, while Youngwood is particularly prominent in securities, M&A and appellate litigation.

Washington, D.C. is a major center for antitrust, investigations and regulatory disputes, led by figures including Sara Razi, Jeffrey Knox and Abram Ellis. California provides meaningful strength in commercial, securities and intellectual-property litigation through Amy Candido, Stephen Blake, Chet Kronenberg and Laura Lin. Zachary Hafer adds investigations and enforcement capability from Boston.

The overall impression is of a sophisticated, nationally integrated litigation practice with the personnel and experience to handle trials, expedited injunctions, regulatory challenges and complex appellate work. Its recent public record is especially persuasive in antitrust, insurance, securities and transaction-related disputes.



Updated October 2026