Sergio A.Tostado


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Sergio Tostado is a litigator and trial lawyer representing clients in complex commercial litigation and government investigations, with an emphasis on compliance matters in the health care industry, antitrust cases, and lawsuits brought by state attorneys general.

Sergio has significant experience defending some of the nation's largest companies in a variety of high-stakes litigation matters. Recent representations include the successful defense of a Fortune 100 company facing a civil RICO class action, as well as the defense of another Fortune 100 company sued by the Kentucky Attorney General for alleged violations of the state's price gouging statute. In addition, Sergio has defended several mergers from antitrust challenges brought by the Federal Trade Commission (FTC), including the successful defenses of two large mergers in the health care industry. Sergio has extensive experience conducting compliance reviews and internal investigations for multinational companies across various industries, with a primary focus on representing companies facing government lawsuits and investigations related to the distribution and dispensing of opioid medications.

Sergio maintains an active pro bono practice. As lead counsel, he obtained a favorable asylum ruling in a contested proceeding and has assisted immigrant children in obtaining lawful permanent residence in immigration court. He was also a key member of the team that successfully represented a death row inmate in his habeas corpus appeal before the Tenth Circuit.

Before joining Jones Day, Sergio clerked for the Honorable Jack Zouhary of the United States District Court for the Northern District of Ohio. Sergio is active in his church.


  • Insurance company obtains full victory in nationwide putative class actionJones Day secured a full victory for a large national insurance company and several affiliated entities in a nationwide putative class action asserting RICO fraud claims and wage and hour claims in connection with the client’s design and operation of several independent contractor agent programs
  • FirstEnergy lands Ohio Supreme Court victory in appeal over energy efficiency programsJones Day represented FirstEnergy Corp. and its three Ohio utilities, Ohio Edison Company, The Cleveland Electric Illuminating Company, and The Toledo Edison Company, in regulatory proceedings before the Public Utilities Commission of Ohio ("PUCO") in connection with FirstEnergy's energy efficiency and peak demand reduction portfolio plans.
  • Marathon Petroleum and Speedway successfully settle lawsuit alleging violations of Kentucky's price gouging statuteJones Day settled on favorable terms, and obtained dismissal of clients Marathon Petroleum Company and its affiliate, Speedway LLC, a lawsuit brought by the Kentucky Attorney General.
  • Cabell cleared to acquire St. Mary's following dismissal of FTC antitrust lawsuit to block transactionAfter a nearly two-year fight with the U.S. Federal Trade Commission, Cabell Huntington Hospital, Inc. has overcome all regulatory hurdles to its acquisition of St. Mary’s Medical Center, Inc., clearing the way to combine Huntington, West Virginia’s only two health systems.
  • Cable company wins favorable U.S. Supreme Court ruling denying plaintiff’s "sham litigation" appealThe U.S. Supreme Court on April 23, 2018, denied the request of a Puerto Rican telecommunications company to hear the appeal of its claims against Jones Day client San Juan Cable, a subsidiary of Liberty Global (the world's largest international TV and broadband company), bringing an end to the long-running antitrust case. 
  • Insurance company obtains dismissal in putative class actions asserting Medicare secondary payer claimsJones Day obtained dismissals on behalf of an insurance company in two related putative class actions brought in the Southern District of Ohio alleging liability under the Medicare Secondary Payer provision of the Medicare Act.
  • Experian secures summary judgment in lawsuit challenging adequacy of credit reporting systemJones Day successfully represented Experian Information Solutions, Inc. in a case brought in the Eastern District of Kentucky alleging liability under the Fair Credit Reporting Act (“FCRA”).
  • Honduran woman obtains asylum in contested immigration caseJones Day represented pro bono a woman from Honduras in connection with the Firm’s Laredo Project.
  • LeBaronBrown Industries invests in Charkit Chemical CompanyJones Day advised LeBaronBrown Industries, LLC in connection with its investment in Charkit Chemical Company, LLC, a supplier of specialty chemicals for the personal care and aroma, food and food additives, imaging and photographic, pharmaceutical, and metal and water treatment industries, among others.
  • Experian resolves putative class action lawsuit over permissible purpose provision of FCRAJones Day represented Experian Information Solutions, Inc. in a putative data privacy class action brought by plaintiffs attempting to certify a class of more than 100 million consumers.
  • Experian resolves putative class action over misuse of sensitive credit data by debt relief businessJones Day represented Experian Information Solutions, Inc. in a putative data privacy class action brought by consumers alleging that Experian failed to take proper precautions to safeguard their personal credit data from an individual in Florida who had engaged in a massive fraud.
  • Custodial bank successfully defends against Department of Justice pay-to-play investigationJones Day successfully represented a custodial bank in a Department of Justice investigation involving pay-to-play allegations related to the bank's contract with a state treasurer to hold billions of dollars in public pension assets.
  • STERIS defeats FTC's attempt to block Synergy Health acquisition on antitrust groundsIn a rare litigation defeat against the Federal Trade Commission, Ohio based STERIS Corporation prevailed against an antitrust challenge brought in federal court by the FTC, which sought to block STERIS's proposed $1.9 billion acquisition of Synergy Health plc.
  • Academic medical center secures Sixth Circuit victory affirming dismissal of False Claims Act actionJones Day obtained a Sixth Circuit decision affirming the dismissal of a False Claims Act action and several state law claims brought against an academic medical center, a surgeon, and other employees of the hospital.
  • Death row inmate secures writ of habeas corpus from Tenth Circuit Court of AppealsOn June 14, 2013, the United States Court of Appeals for the Tenth Circuit ordered the United States District Court for the Eastern District of Oklahoma to issue a writ of habeas corpus to the Oklahoma state courts for David Magnan.
    • November 11, 2013
      Jones Day hosts LCLD Group Mentoring Sessions for first year law students at Ohio State University and Capital Law School
    • January 23, 2013
      Jones Day Columbus coordinates and presents LCLD Group Mentoring Meeting at Ohio State University Moritz College of Law