Small Business vs. the Agency: Challenging Federal Rules and Enforcement in the Post-Chevron Era

Samantha Chaifetz, Partner and Co-Chair, Appellate Advocacy Practice | DLA Piper LLP (US)

Samantha Chaifetz is a Partner in the Washington, DC office of DLA Piper and Co-Chair of the firm’s Appellate Advocacy practice. A nationally recognized appellate litigator with roughly two decades of experience in complex civil appeals raising constitutional, statutory, and administrative law questions, she has served as appellate counsel in more than 100 matters, presented oral argument in more than 40 federal appeals, and argued before 10 federal circuits — frequently on issues of first impression. Before joining DLA Piper in 2023, she spent fifteen years as a lead appellate attorney in the Civil Division of the U.S. Department of Justice, where she defended agency action under the Administrative Procedure Act, handled challenges to federal statutes including the Affordable Care Act, prepared Supreme Court filings, and represented all 15 federal executive departments. She has also held senior legal posts in the White House and the U.S. Senate. Today she represents life sciences and technology companies in multidistrict and class actions, foreign banks in cross-border disputes, and regulated entities in administrative challenges, and she is a Lecturer on Law at Harvard Law School.

• Education & Credentials

Ms. Chaifetz earned her J.D. from Yale Law School in 2005, where she was a Senior Editor of the Yale Law Journal and Co-Editor-in-Chief of the Yale Journal of Health Policy, Law, and Ethics, and her B.A., magna cum laude and Phi Beta Kappa, from Harvard College in 2000. She began her career clerking for Judge Betty B. Fletcher of the U.S. Court of Appeals for the Ninth Circuit and Judge Louis H. Pollak of the U.S. District Court for the Eastern District of Pennsylvania. She is admitted to practice in New York and the District of Columbia and before the Supreme Court of the United States; the U.S. Courts of Appeals for the District of Columbia, First, Second, Fourth, Fifth, Sixth, Ninth, and Eleventh Circuits; and the U.S. District Courts for the Southern and Eastern Districts of New York.

• Recognition & Leadership

Ms. Chaifetz has been named to the Lawdragon 500 Leading Litigators in America for 2026 and 2027. She received DLA Piper’s Americas Pro Bono Award in 2025 and has been named to the DC Courts Capital Pro Bono Honor Roll in 2023, 2024 (High Honor Roll), and 2025. During her government service she received the Attorney General’s Exceptional Service Award — the Department of Justice’s highest honor — and a Civil Division Special Commendation for the defense of the Affordable Care Act (2013), the Environment and Natural Resources Division’s Award for Excellence for FOIA litigation (2013), a Civil Division Special Commendation for the defense of the Adam Walsh Act (2012), the Federal Bar Association’s Younger Federal Lawyer Award (2012), and a Civil Division award for the defense of a class action (2008). Her service spans all three branches of government: she was Deputy Counsel to the Vice President from 2021 to 2022, where her portfolio included legal issues before the National Space Council; Counsel to the U.S. Senate Judiciary Committee’s Subcommittee on Privacy, Technology and the Law from 2014 to 2015; and a member of the White House Office of Communications in 2010. She is a Master of the Edward Coke Appellate Inn of Court and a member of the Women’s Bar Association of the District of Columbia, and she teaches “Legal Profession: Government Lawyering” as a Lecturer on Law at Harvard Law School.

• Professional Involvement

Ms. Chaifetz is a leading commentator on the post-Chevron regulatory landscape. She co-authored “Chevron Overruled: Loper Bright v. Raimondo and the Changing Federal Regulatory Landscape” (Texas Practical Business Law Journal, June 2025), “Why Now Might Be a Great Time to Sue the Government” (The Legal Intelligencer, November 2024), and “White House Announces National Fraud Enforcement Division: Top Points” (Journal of Federal Agency Action, May–June 2026). Her recent speaking engagements include PLI’s “Appellate Advocacy: Strategic Choices in Trial Courts” (April 2026); LegalWeek’s “Deep Dive: Future State of the Industry” (March 2026); a DLA Piper roundtable on the EPA’s withdrawal of its greenhouse gas endangerment finding (February 2026); a Strafford webinar on the Supreme Court’s rulings for regulated industries (December 2024); American Bar Association Section of Taxation panels on Chevron deference (2024); DLA Piper’s Washington Matters podcast and Policy Matters panel on counseling clients after Chevron (September 2024); the Appellate Judges Education Institute Summit on persuasive brief writing (November 2023); and CLE panels at the ABA Administrative Law Conference from 2020 through 2022. Her analysis has been featured by Bloomberg Law on how the Supreme Court’s rulings have opened new avenues to challenge regulations, by STAT on the Court’s limits on regulators’ authority, and by Modern Healthcare, Law360, Reuters, Bloomberg News, and Courthouse News Service.

• Experience

Ms. Chaifetz has spent her career on both sides of the government-litigation divide. For fifteen years at the Department of Justice she defended federal statutes and agency action against constitutional and APA challenges, with reported appellate victories spanning health care, privacy, the First Amendment, and the False Claims Act. At DLA Piper she has defended, in the U.S. Court of Appeals for the Fifth Circuit, the dismissal of a putative class action brought against a global cybersecurity vendor following a major technology outage; represented foreign banks in cross-border contract disputes at the trial and appellate levels, including a closely watched New York appeal concerning international money transfers; represented pharmaceutical and medical device companies in state and federal misbranding suits; advised clients on pre-litigation strategy for emerging state consumer product regulations; counseled an overseas client on defamation exposure arising from social media; and worked alongside the firm’s government affairs team to oppose proposed state legislation. Having defended agency rules from inside the Justice Department and now challenging them on behalf of regulated clients — and having written and lectured extensively on what Loper Bright changes for the regulated community — Ms. Chaifetz is uniquely positioned to show practitioners how small businesses can challenge federal rules and enforcement in the post-Chevron era.

Varu Chilakamarri, Partner | K&L Gates LLP

Varudhini “Varu” Chilakamarri is a Partner in the Washington, DC office of K&L Gates and a member of the firm’s Environment, Land, and Natural Resources practice group, where her work spans appellate litigation, administrative and regulatory law, environmental and energy matters, mass tort, and product liability. She joined K&L Gates in December 2023 after approximately 17 years at the U.S. Department of Justice, most recently as Deputy Assistant Attorney General in the Civil Division, where she oversaw the Torts Branch and the defense of the United States in damages suits nationwide. A veteran appellate advocate, she has argued cases in the U.S. Courts of Appeals for the Third, Fifth, Ninth, Tenth, District of Columbia, and Federal Circuits, and two preemption cases she worked on reached the Supreme Court of the United States. Since Loper Bright, Ms. Chilakamarri has become one of the most frequently quoted voices on the end of Chevron deference and the future of agency power — cited by Law360, Bloomberg Law, USA Today, the Financial Times, The Hill, Inside EPA, and Reuters — and she advises clients on the legal risks and opportunities that arise when the federal government is a counterparty, regulator, or adversary.

• Education & Credentials

Ms. Chilakamarri earned her J.D. from Georgetown University Law Center in 2004, where she received the Leon Robbin Gold Medallion in Patent Law, and her B.A. and B.S. from The Ohio State University in 2001. She clerked for Judge R. Guy Cole Jr. of the U.S. Court of Appeals for the Sixth Circuit and Judge Timothy Dyk of the U.S. Court of Appeals for the Federal Circuit. She is admitted to practice in the District of Columbia and New York and before the Supreme Court of the United States; the U.S. Courts of Appeals for the District of Columbia, Fourth, Sixth, and Tenth Circuits; and the U.S. District Court for the District of Columbia.

• Recognition & Leadership

Ms. Chilakamarri is recommended by The Legal 500 United States for Environment: Litigation (2025 and 2026). Her Department of Justice honors include the Attorney General’s Award for Outstanding Service (2013), Environment and Natural Resources Division Outstanding Performance Awards (2016, 2018, and 2020), the Civil Division Special Commendation Award (2012), and the Civil Division Perseverance Award (2010), and she received the ABA/BNA Award for Excellence in Intellectual Property in 2004. Over the course of her government career she rose through a series of leadership and policy roles: she joined the Department in 2006 through the Attorney General’s Honors Program as a trial attorney in the Civil Division’s Federal Programs Branch, served as Acting Deputy in the Office of the Associate Attorney General, was detailed to the White House Counsel’s Office, served as an Ex Officio Member of the Department’s State Secrets Review Committee (2013–2014), became the Environment and Natural Resources Division’s first counselor for animal welfare matters, served as Chief of Staff to the Assistant Attorney General for that Division, and ultimately led the Civil Division’s Torts Branch as Deputy Assistant Attorney General.

• Professional Involvement

Ms. Chilakamarri is a prolific author and speaker on administrative law after Chevron. Her publications include “The End of Chevron Deference: What the Supreme Court’s Ruling in Loper Bright Means for the Regulated Community” (The Journal of Federal Agency Action, 2024), “3 Ways Agencies Will Keep Making Law After Chevron” (Law360, 2024), “How DOGE’s Bite Can Live Up To Its Bark” (Law360, 2025), “States and Federal Rules Conflict Over Food, Food Packaging Regulations” (Packaging Digest, 2025, co-author), and “APA Litigation: Procedural Mechanisms that Focus Environmental Controversies” (Rocky Mountain Mineral Law Foundation, 2019), as well as scholarly articles in the Virginia Journal of Law & Technology, Animal Law, and the Georgetown Law Journal. From 2024 through 2026 she has spoken on post-Loper Bright administrative law and the limits of agency power for ALI CLE, the ABA Section of Litigation, the Federalist Society, the National Association of Women Lawyers, and a Harvard Law School symposium; on the major questions doctrine at the Administrative Law Spring Conference; on energy emergency powers and NEPA reform for the Federalist Society and the Environmental Business Journal; on water quality and toxic contaminants for the ABA Section of Environment, Energy, and Resources; on natural resources and energy law for the Foundation for Natural Resources and Energy Law; and on regulatory issues facing the chemical industry for the Chemical Industry Council of Illinois. She has also presented at a Harvard Law School conference on the Animal Welfare Act and spoken on careers and leadership for the South Asian Bar Association of DC and the Women’s Bar Association.

• Experience

Ms. Chilakamarri’s practice is built on nearly two decades of litigating for and against the federal government at the highest levels. As Deputy Assistant Attorney General she oversaw the Torts Branch’s defense of the United States in toxic tort, constitutional tort, and statutory compensation cases, including damages suits arising from environmental regulatory actions. As an appellate attorney in the Environment and Natural Resources Division she served as lead counsel in complex civil and criminal appeals, including facial constitutional challenges to federal statutes and challenges to permitting and land use decisions under the National Environmental Policy Act, the Endangered Species Act, and the Clean Water Act, and she litigated environmental enforcement actions. As a trial attorney in the Federal Programs Branch she defended agency action against APA and constitutional challenges in the district courts. At K&L Gates she now puts that experience to work for the regulated community, litigating appellate, administrative, environmental, and energy matters and advising clients in the energy and transportation and logistics industries on regulatory requirements, the lawfulness of agency action, and where the post-Chevron doctrines — Loper Bright, the major questions doctrine, and the APA’s procedural requirements — create leverage. Having defended federal rules and permitting decisions in the courts of appeals for most of her career, and now counseling businesses on how to challenge them, Ms. Chilakamarri is uniquely positioned to guide practitioners through challenging federal rules and enforcement in the post-Chevron era.

Josh Gardner, Partner | DLA Piper LLP (US)

Joshua (Josh) Gardner is a Partner in the Washington, DC office of DLA Piper, where he practices in the firm’s Litigation, Arbitration and Investigations and Regulatory and Government Affairs groups. A firstchair trial and appellate attorney, he handles high-stakes litigation, appeals, congressional investigations, and regulatory disputes arising from federal and state government action, drawing on more than two decades of experience in private practice and at the U.S. Department of Justice, including more than a dozen bench and jury trials in district courts across every federal circuit. Before joining DLA Piper in 2025, Mr. Gardner held senior roles in the Civil Division across five presidential administrations — most recently as Acting Deputy Director and Special Counsel of the Federal Programs Branch, the office charged with defending federal agencies and their regulations against constitutional and Administrative Procedure Act challenges — and served as Acting Chief of Staff of the Department’s Office of Legislative Affairs. He now represents corporations, financial institutions, health care organizations, energy companies, and trade associations in commercial litigation, toxic tort and product liability matters, constitutional and regulatory challenges, and appeals, and he serves as outside counsel to Lawyers for Civil Justice on federal rulemaking and civil justice reform.

• Education & Credentials

Mr. Gardner earned his J.D. from The George Washington University Law School and his B.A. from the University of Central Florida. Following law school he served as a law clerk to Justice Barbara J. Pariente of the Supreme Court of Florida from 2000 to 2002. He is admitted to practice in the District of Columbia and Florida and before the Supreme Court of the United States; the U.S. Courts of Appeals for the District of Columbia, Second, Eleventh, and Federal Circuits; the U.S. District Courts for the District of Columbia and the Southern District of Florida; the U.S. Bankruptcy Court for the Middle District of Florida; and the U.S. Court of Federal Claims.

• Recognition & Leadership

Mr. Gardner received the Presidential Rank Award in 2024, one of the highest honors available to career members of the federal government’s senior executive corps, and the Attorney General’s John Marshall Award for Trial of Litigation in 2007, among the Department of Justice’s most prestigious recognitions for its attorneys. His Department of Justice honors also include Civil Division Special Commendation Awards (2010 and 2024), the Department’s Special Commendation Award (2014), its Training & Professional Development Award (2015), and the U.S. Department of Agriculture’s Honors Award (2011). In addition to leading the Federal Programs Branch as Acting Deputy Director and Special Counsel, he served as Acting Chief of Staff of the Office of Legislative Affairs — managing congressional information requests and preparing Department witnesses for testimony — and worked with the Advisory Committee on Civil Rules on amendments to the Federal Rules of Civil Procedure. A dedicated teacher of trial advocacy, evidence, and legal ethics, Mr. Gardner has been a Professorial Lecturer in Law at The George Washington University Law School since 2004, a Lecturer on Law at Harvard Law School (2025), and an instructor at the Department of Justice’s National Advocacy Center since 2008, and he regularly trains government agencies, U.S. Attorney’s Offices, and private organizations.

• Professional Involvement

Mr. Gardner serves as outside counsel to Lawyers for Civil Justice on federal rulemaking and civil justice reform. He is the author of “Demystifying the Civil Procedure Rules Amendment Process” (Law360, September 2025) and co-author of “How to Address Three Big Challenges That Mar Corporate Testimony” (Bloomberg Law, December 2025) and “White House Announces National Fraud Enforcement Division: Top Points” (Journal of Federal Agency Action, May–June 2026). His recent speaking engagements include a Barbri panel on drug label litigation and impossibility preemption (July 2026); a myLawCLE program on presenting and objecting to evidence (2026); a DLA Piper roundtable on the EPA’s withdrawal of its greenhouse gas endangerment finding (February 2026); the U.S. Army Legal Services Agency’s Federal Litigation Course, where he taught sessions on depositions and on temporary restraining orders and preliminary injunctions (September 2025); and the UC Berkeley School of Law “Iqbal at 15” symposium (August 2025). He has been quoted by Law360 on federal workforce, DOGE, and agency litigation developments and by the Anti-Corruption Report on privilege in internal investigations, and his recent client alerts address the D.C. Circuit’s treatment of congressional subpoenas, the Supreme Court’s decision overruling Humphrey’s Executor, and the Court’s landmark donor-privacy ruling in First Choice.

• Experience

Mr. Gardner has tried and argued some of the most consequential government-facing cases of the past two decades. At the Department of Justice he served as lead counsel in the First Amendment and APA class action challenging federal communications with social media platforms — a case that reached the Supreme Court, which held that the plaintiffs lacked standing; as lead counsel for the United States in what was then the largest federal government data breach litigation; as lead trial attorney in multiple trials over the 2020 census citizenship question; as co-lead trial counsel in a nine-week trial of AIG shareholders’ roughly $40 billion damages claim against the United States, in which the trial court awarded no damages and the Federal Circuit later reversed the liability finding; and as lead or co-counsel in nine trials of spent nuclear fuel delay-damages claims against the Department of Energy. At DLA Piper he represents a health care coalition challenging actions of the U.S. Department of Health and Human Services; a multinational pharmaceutical, agricultural, and life sciences company in toxic tort and product liability suits; foreign banks in commercial litigation in federal district court; and a major physician-services organization in resolving a contract dispute. He represented a former FDA Chief Counsel as amicus curiae supporting a Supreme Court certiorari petition concerning the Inflation Reduction Act, advised a cleanenergy and hydrogen technology company on a Department of Energy financing agreement, and counseled an energy technology client on a proposed federal-sector energy project. His pro bono practice includes constitutional and statutory challenges on behalf of individuals and organizations. Having spent two decades defending federal agencies and their rules from inside the Federal Programs Branch — and now representing the regulated community in challenging agency action — Mr. Gardner is uniquely positioned to explain how small businesses can take on the agency in the post-Chevron era.

Robert S. Silverblatt, Partner | K&L Gates LLP

Robert (Rob) S. Silverblatt is a Partner in the Washington, DC office of K&L Gates and a member of the firm’s White Collar Defense and Investigations practice group, where his work also spans tax controversy and litigation and U.S. congressional investigations. A former U.S. Department of Justice trial attorney with substantial experience serving as lead counsel on legally and factually complex cases, he represents companies and individuals in matters before the Department of Justice and the Securities and Exchange Commission — from civil False Claims Act litigation to criminal investigations and prosecutions — as well as in congressional investigations, IRS audits and tax litigation, and internal investigations. From 2016 to 2021 he served as a trial attorney in the Tax Division of the U.S. Department of Justice, where he litigated tax shelter, fraudulent transfer, undisclosed foreign bank account, tax preparer injunction, and alter ego cases in federal district and bankruptcy courts across the country and was honored with the Department’s Outstanding Attorney award in three consecutive years. Now on the other side of the table, he prepares chief executives and senior officers for interviews and testimony before Congress and grand juries, helps clients identify and remediate legal and reputational risk, and advises on the shifting boundaries of federal enforcement power — including the growing body of post-Jarkesy and post-Loper Bright challenges to agency penalty authority.

• Education & Credentials

Mr. Silverblatt earned his J.D., magna cum laude, from Georgetown University Law Center in 2013, where he was elected to the Order of the Coif, and his B.A., magna cum laude, from Tufts University in 2009. He served as a law clerk to Judge Thomas L. Ambro of the U.S. Court of Appeals for the Third Circuit from 2015 to 2016. He is admitted to practice in the District of Columbia and Virginia and before the Supreme Court of the United States; the U.S. Courts of Appeals for the First, Second, Third, and Fifth Circuits; the U.S. District Courts for the District of Columbia and the Eastern and Western Districts of Michigan; and the United States Tax Court. He is also proficient in Spanish.

• Recognition & Leadership

Mr. Silverblatt is recognized by The Legal 500 United States as a Recommended Lawyer for 2026 in three separate categories: Corporate Investigations and White-Collar Criminal Defense; Government Relations; and U.S. Taxes: Non-Contentious. During his service at the Department of Justice he received the Tax Division’s Outstanding Attorney award in 2018, 2019, and 2020. He was elected to the K&L Gates partnership effective January 1, 2024, among a class of nearly 30 new partners across the firm’s global offices. He serves as a Civic Director of the Council for Court Excellence, the nonpartisan civic organization dedicated to improving the administration of justice in the District of Columbia, and is a Fellow of the American Bar Foundation, an honor extended to a small fraction of the legal profession in recognition of professional achievement and commitment to the welfare of the community.

• Professional Involvement

Mr. Silverblatt writes and speaks regularly on the evolving limits of federal enforcement authority. His thought leadership includes “Congressional Investigations: What to Expect in the 120th Congress” (August 2026); “Prosecutor, Jury, and Judge? Courts Split on IRS Penalty Power Post Jarkesy” (September 2025), examining the Supreme Court’s Seventh Amendment limits on agency-imposed civil penalties; “President Trump Orders FCPA Freeze; DOJ Announces Major Policy Realignment De-Emphasizing Corporate Investigations and Enforcement” (February 2025); “Dialing for Dollars: US Department of Justice Announces New Whistleblower Pilot Program” (March 2024); and “DOJ Announces Major Changes to Corporate Criminal Enforcement Policies” (Westlaw Today powered by Reuters, November 2021). His recent speaking engagements include a panel on “Sun, Sand, and Scrutiny: IRS Enforcement of Puerto Rico Act 22 Residency” (October 2025), the ABA Criminal Tax Fraud and Tax Controversy Conference (2024), and the ABA May Tax Meeting (2023). His commentary on federal enforcement has been featured by Tax Notes on the government’s selection of Puerto Rico Act 60 criminal cases (November 2025), by MLive on a Michigan nursing home’s $4.9 million tax refund suit against the IRS (September 2025), by the Virginia Mercury and Yahoo! News on a motion to dismiss a False Claims Act suit alleging a fraudulent ownership scheme (July 2024), by Law360 on an $18.4 million FBAR penalty sought from a Texaco heiress’s estate and on a Florida tax preparer barred over fraudulent returns (2021), and by The Philadelphia Inquirer (2017).

• Experience

Mr. Silverblatt’s practice is built on experience litigating both for and against the federal government. He began his career at K&L Gates in 2013 as an associate in the Government Enforcement practice, representing clients in matters before the SEC, the Federal Energy Regulatory Commission, the Commodity Futures Trading Commission, and FINRA. As a Department of Justice trial attorney he served as lead counsel in tax shelter, fraudulent transfer, foreign bank account, tax preparer injunction, and alter ego matters, taking depositions, conducting evidentiary hearings, and trying cases in federal district and bankruptcy courts, with his work featured in Law360’s coverage of an $18.4 million FBAR penalty action, a permanent injunction against a fraudulent tax preparer, and an Eleventh Circuit decision affirming a $2.8 million tax judgment against a business owner who siphoned company funds. Since rejoining K&L Gates in 2021 he has represented companies and individuals in DOJ and SEC investigations, defended False Claims Act litigation — including as part of the K&L Gates team that secured a victory for Ocean Harvesters in a whistleblower lawsuit (2025) and a significant Second Circuit False Claims Act appellate win (2026) — handled IRS controversies involving the employee retention credit, transferee liability, research and development credits, and charitable donation deductions, and guided executives through congressional inquiries and grand jury testimony. Having enforced federal law from inside the Justice Department and now defending businesses against it — and having written on how Jarkesy and the Supreme Court’s recent separation-of-powers decisions constrain agency penalty power — Mr. Silverblatt is uniquely positioned to show practitioners how small businesses can push back against federal enforcement in the postChevron era.

SESSION 1 – The New Playbook: Loper Bright, Corner Post, and Jarkesy Two Years On | Varu Chilakamarri & Robert S. Silverblatt | 12:00pm – 1:00pm

The session will examine what Loper Bright changed about judicial review of agency statutes and what remains of deference under Skidmore, express congressional delegations, and agency factual findings. It will also explore how agencies continue to shape law and policy after Chevron. The discussion will turn to Corner Post and the potential to challenge longstanding regulations when a new injury arises, including the statute-of-limitations and finality defenses the government raises and how federal appellate courts have addressed these issues. It will then analyze Jarkesy and the constitutional right to a jury trial in agency enforcement proceedings, identifying penalty regimes that may be vulnerable to challenge, strategies for moving disputes into Article III courts, and how the Department of Justice and federal agencies are adapting their enforcement approaches. Drawing on the perspectives of former DOJ lawyers, the session will conclude with an inside look at how government litigators defend agency action after Chevron, including their leading arguments, administrative record strategies, and potential vulnerabilities that small-business challengers can exploit.

BREAK | 1:00pm – 1:10pm

SESSION 2 – Taking the Government to Court: Affirmative Challenges for Small Businesses | Samantha Chaifetz & Josh Gardner | 1:10pm – 2:10pm

The session will provide an inside look at how the Department of Justice evaluates, defends, and resolves challenges to federal agency action, including the government’s litigation strategies and considerations that shape its decisions. It will examine the procedural hurdles challengers must overcome to get into federal court, including standing, ripeness, venue, and exhaustion requirements. The discussion will then address emergency relief following Trump v. CASA, comparing temporary restraining orders, preliminary injunctions, stays under APA § 705, and vacatur as tools for challenging agency action. Participants will also explore how to build a persuasive case through the administrative record, identify gaps in the government’s evidence, and preserve arguments for appellate review. Finally, the session will consider avenues beyond the Administrative Procedure Act, including money claims before the U.S. Court of Federal Claims, challenges to grant and contract terminations, and structural constitutional challenges in light of Humphrey’s Executor.