Nelson Hardiman - HealthCare Lawyers

Zachary Rothenberg

Zachary Rothenberg
Zachary Rothenberg

T: 310.203.2800
F: 310.203.2727

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State Bar of California


American Health Lawyers Association

Beverly Hills Bar Association, Health Law Committee
(Executive Committee)

California Society for Healthcare Attorneys
(Education Committee)

California Young Lawyers Association
(Past Board of Directors)

Los Angeles County Bar Association, Healthcare Law Section
(Executive Committee)



Harvard Law School, J.D.
Columbia, B.A.

Perseverance, versatility, and efficiency. These are attributes that serve Zachary Rothenberg when he’s competing in a triathlon – his preferred athletic endeavor – but also define his approach in litigation. Zach has spent more than a decade-and-a-half litigating business disputes in federal and state courts and in arbitration. He has represented clients in diverse industries including entertainment, professional services, financial services, marketing, and manufacturing. As a partner at Nelson Hardiman, Zach leverages his broad knowledge of industries and business models to advise healthcare clients.

Focused on Litigation Solutions Across a Broad Spectrum of Providers and Issues

Zach regularly represents healthcare clients in cases involving breach of contract, fraud, unfair competition, and misuse of trade secrets. His clients have ranged from individual doctors, nurses, and other individual healthcare providers, to ambulatory surgery centers, pharmacies, and drug rehabilitation facilities, to hospitals and Independent Practice Associations (“IPAs”).

Strong Experience with Behavioral Health Providers

Zach has a breadth of knowledge in the behavioral health space. He advises drug rehabilitation facilities on land use, advocating for clients where administrative actions challenge zoning laws, attempting to prevent facilities from operating in their existing location. He litigates out-of-network and in-network reimbursement cases on behalf of addiction treatment facilities and responds to special investigation audits. He has also advised on labor and employment defense matters including those related to racial discrimination, wrongful termination, wage & hour disputes, and retaliation. Clients have come to rely on his insight regarding employee handbooks and labor code issues.


Zach was named to the Southern California Rising Stars list for seven consecutive years (2008-2014) and has been included on the Super Lawyers list for the past four years (2017-2020).

Life Outside the Firm

Outside the courtroom, Zach has utilized that same litigation tenacity to post a sub 6-hour Half Ironman triathlon race. His idea of fun is cycling along Mulholland Drive or the Pacific Coast Highway in a nifty spandex outfit (and helmet, of course) preparing for his next race. For many years, Zach spent his evenings catching live music all around town, but, now a dad, he is resigned to the living room with his Spotify account and a nice single malt.

  • Business Litigation When a father of a teenager being treated for addiction wrongfully pocketed more than $100,000 in insurance proceeds to buy a house instead of reimbursing a recovery facility, Zach filed multiple actions against the father including for unjust enrichment and fraud. The case was further complicated by the fact that the father never signed any contracts with the rehab facility and worked out of state. However, Zach was able to serve the defendant through some unique sleuthing efforts and dogged determination. In the end, he won a full judgment plus interest against the father.
  • Employment Dispute Settled a whistle-blower retaliation matter on behalf of an Orange County addiction treatment company for pennies on the dollar after a Nelson Hardiman investigation led to the discovery of employment information that substantially weakened the claimant’s case.
  • Employment Litigation Represented a bariatric surgeon in bringing contract, tort, and Labor Code claims against a former employer/medical practice represented by the litigation department chair for a national law firm. After five-day arbitration, client was awarded 100% of unpaid wages, interest, civil penalties, and attorneys’ fees.
  • Employment Litigation Represented a nurse in pre-litigation efforts to resolve a dispute with a former physician-employer alleging misappropriation of trade secrets, fraud, and unfair competition based on nurse’s communications with patients announcing her departure.
  • First Amendment/Anti-SLAPP: Represented pharmacist serving as class representative in large class action against dietary supplement manufacturer. Pharmacist was named as defendant in cross-action claiming that he had slandered supplement manufacturer in online video and television video discussing the nature of the class action lawsuit. Zach filed an “anti-SLAPP” motion to strike the cross-claims, arguing that his comments were protected speech under the First Amendment. The cross-claims against Zach’s clients were stricken and he was awarded all of his attorney’s fees.
  • Intellectual Property: Represented internet retailer of dietary supplements in multi-party federal court trademark infringement litigation. Zach leveraged deposition testimony and documents produced in discovery to convince the plaintiffs that his client was not one of the “bad actors” and to settle Zach’s client out of the case on favorable terms.
  • Land Use Litigation Represented addiction treatment facility facing public nuisance action brought by city government that jeopardized the facility’s ability to continue operating. After lengthy negotiations, Zach was able to convince the city that the facility posed no threat to the communication.  The City agreed to dismiss the case, with prejudice, without any payment of money.
  • Managed Care Represented IPA in a five-year action against a laboratory, defending against numerous claims and legal theories seeking more than $1.5 million for lab testing performed after termination of the parties’ agreement. Following five days of arbitration, arbitrator dismissed all but one claim, reducing potential exposure to a fraction of the claimed amount.
  • Municipal Law Represented sober living home in dispute with city government. Zach was able to employ his knowledge of Fair Housing Act (“FHA”) and Americans with Disabilities Act (“ADA”) to negotiate an agreement unique to his client that enabled the facility to continue operations as-is.
  • Reimbursement Represented an ambulatory surgery center in out-of-network “fee forgiveness” action against a major insurance company. Pursuing in excess of $3 million for claims improperly denied based on claim that surgery center “forgave” patient contribution as inducement for using out-of-network facility.  Obtained successful rulings on: motion to remand from Federal Court, demurrers, motions to compel discovery.
  • Unfair Competition Obtained a permanent injunction on behalf of a Los Angeles medical marijuana dispensary, as part of a global settlement with an illegal competitor business.
  • Qui Tam (“Whistleblower”) Defense Settled a potential large whistle-blower lawsuit on behalf of an addiction treatment facility. In addition to potential false claims act violations, a former employee alleged a hostile work environment (constructive discharge) and retaliation. Sensing an opportunity with an eager plaintiff, Zach proposed an unusual pre-filing mediation, which resulted in a quick settlement for a fraction of the original demand amount.
  • Hospital Litigation Obtained permanent injunction against hospital patient who had refused to leave the hospital despite lacking medical necessity.
  • Hospital Operations Helped California independent hospital system develop a toolkit to address various discharge challenges, including those involving unrepresented and homeless patients as well as payment for extended hospital stays.
  • Fair Housing Rights Resolved disputes with five cities across California regarding complaints concerning behavioral health housing.
  • Hospital Litigation Nelson Hardiman was able to persuade a patient, who had refused to be discharged for 18 months and refused to pay the hospital, to agree to be discharged. Then Nelson Hardiman filed a lawsuit against the patient and won a three-week trial recovering the monies owed to the hospital.


Client Alert: MultiPlan Named As Central Figure In Antitrust Lawsuit Alleging Health Insurance Monopoly Scheme

November 11, 2021

Nelson Hardiman Successfully Resolves Medi-Cal Recoupment Litigation for Medical Supplies Client

July 27, 2021

Modern Healthcare: UnitedHealth’s limits on out-of-network care seen as surprise billing ban reaction

July 8, 2021

Nelson Hardiman successfully resolved whistleblower claims brought against multiple firm clients under the Insurance Frauds Prevention Act

July 6, 2021

Client Alert: Optum Abruptly Cuts OON Benefits

June 28, 2021

A View from Legal Street, Help Us Help You Get Paid, Episode 11: Disability Insurance

May 17, 2021

A View from Legal Street, Help Us Help You Get Paid, Episode 10: Revenue Cycle and Quality of Earnings

April 22, 2021

Commercial Insurers Hitting More and More Behavioral Providers with Audits, Repayment Requests

March 29, 2021

A View from Legal Street, Help Us Help You Get Paid, Episode 9: Data to Drive Healthcare Businesses to Maximize Reimbursement

February 8, 2021

8 Nelson Hardiman Attorneys Named to the 2021 Southern California Super Lawyers List

January 28, 2021

Nelson Hardiman Attorneys Salvatore Zimmitti and Zachary Rothenberg Defeat Summary Judgement Motion by United Healthcare

November 25, 2020

A View from Legal Street, Help Us Help You Get Paid, Episode 8: Documentation & Medical Necessity

November 24, 2020

A View from Legal Street, Help Us Help You Get Paid, Episode 7: Medical Records, The Hearsay Rule, & Exceptions to The Rule

November 9, 2020

A View from Legal Street, Help Us Help You Get Paid, Episode 6: Accounting & Tax Implications of Healthcare Reimbursement

September 15, 2020

Ten Steps to Reimbursement Success: How to Help Your Attorney Help You Get Paid

September 10, 2020

A View from Legal Street, Help Us Help You Get Paid, Episode 5: Behavioral Health Commercial Insurance Reimbursement

August 24, 2020

A View from Legal Street, Help Us Help You Get Paid, Episode 4: 365 Day Rule

August 6, 2020

Recoupment Demands: A View from Legal Street, Help Us, Help You Get Paid, Episode 3

July 1, 2020

A View from Legal Street, Help Us Help You Get Paid, Episode 2: Submitting Timely Appeals

June 10, 2020

A View from Legal Street, Help Us Help You Get Paid, Episode 1: Essential Documentation

May 26, 2020

Ten Things You Can Start Doing Today to Improve Your Commercial Reimbursement Success

April 21, 2020

Maximize Your Cashflow During COVID-19: Four Things You Can Do RIGHT NOW

March 30, 2020

7 Nelson Hardiman Attorneys Named to the 2019 Southern California Super Lawyers List

January 30, 2019

After a banner year of growth, Nelson Hardiman announces new management structure and new partners

December 24, 2018

Trends in Combating Fraud and Abuse in Substance Use Disorder Treatment

September 20, 2018

Nelson Hardiman Attorneys Zachary Rothenberg and Jonathan Radke win injunction for California hospital to remove patient refusing to be discharged

September 13, 2018

Insurers Use Calif. Fraud Law Against Health Providers

May 29, 2018

Nelson Hardiman Investigation Leads to Quick Settlement of Whistle-blower Retaliation Matter

April 4, 2018

4 Nelson Hardiman Attorneys Named to Southern California Super Lawyers List

January 30, 2018

Three Nelson Hardiman Attorneys Complete Palm Springs Triathlon

December 12, 2017

Banner Year of Recognition for Nelson Hardiman

August 16, 2017

Partner Zach Rothenberg Notches Another Litigation Win

June 1, 2017

Nelson Hardiman Settles Whistleblower Lawsuit on Behalf of Addiction Treatment Facility

May 2, 2017

Zachary Rothenberg Wins Full Judgment on Behalf Of Addiction Treatment Facility

April 6, 2017

Nelson Hardiman Partners Selected as California Super Lawyers for 2017

January 26, 2017

Nelson Hardiman obtains permanent injunction on behalf of medical marijuana dispensary

March 9, 2016

Seasoned Business Litigator Joins Nelson Hardiman

January 12, 2016

Nelson Hardiman Doubles Down

January 12, 2016

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The Struggle is Real: The Current Legal and Regulatory Landscape for Substance Use Disorder Providers

BHBA: The Struggle is Real: The Current Legal and Regulatory Landscape for Substance Use Disorder Providers

Dec 09, 2021

COVID-19: Where Are We Today?

LACBA Healthcare Law Section

May 20, 2021

The Collections Continuum: Reimbursement Guide From Treatment to Payment

Nelson Hardiman Healthcare Webinar

Oct 22, 2020

10 Steps to Reimbursement Success: How to Help Your Attorney Help You Get Paid

NCAD 2020 Virtual Conference

Aug 02, 2020

Help Us Help You Get Paid: Ten Things You Can Start Doing Today to Improve Your Commercial Reimbursement Success

Behavioral Health Association of Providers Webinar

Apr 21, 2020

Program Administration/Executive Leadership: Addiction Treatment Provider Compliance

6th Annual California Addiction Conference

Nov 02, 2019

Legal Landscape: Regulations, Revenue and Relationships

Building & Sustaining a Successful Sober Home Business – Best Practices for Sober Home Management

Jan 26, 2019

SUD Treatment Provider Boot Camp

Behavioral Health Association of Providers & Nelson Hardiman Event

Oct 22, 2018

Addiction Treatment Marketing, Ethical Compensation Practices, Part 3 (5 CE)

National Conference on Alcohol & Addiction Disorders | Anaheim, CA

Aug 22, 2018

Addiction Treatment Marketing, Part 2 (5 CE)

National Conference on Alcohol & Addiction Disorders | Anaheim, CA

Aug 21, 2018

Addiction Treatment Marketing, Part 1 (5 CE)

National Conference on Alcohol & Addiction Disorders | Anaheim, CA

Aug 20, 2018

Addicts?!! NIMBYism, YIMBYism and the Current Legal Landscape for Addiction Treatment Providers

Beverly Hills Bar Association, Health Law Committee & Real Estate Section

Jun 28, 2018

West Coast Symposium on Addiction Disorders

WCSAD | La Quinta, CA

Jun 01, 2018

Employment and HR Best Practices for the Recovery Industry

AATA Seminar

Mar 02, 2018

Avoiding Addiction Treatment Fraud and Abuse: What you need to know to get and stay in compliance

Annual Healthcare Enforcement Compliance Institute | Washington, D.C.

Oct 29, 2017

Navigating the Evolving Regulatory and Reimbursement Landscape

30th Annual CCSAD Cape Cod Symposium on Addictive Disorders | Hyannis, MA

Sep 14, 2017

Best Practices in Marketing, Drug Testing, Treatment, and Reimbursement

Behavioral Healthcare Executive Series | Scottsdale, AZ

Jun 08, 2017

Special Investigations Unit: What to Know in a Commercial Payer Audit

American Addiction Treatment Association

Apr 13, 2017

Making an Impact on The Business Side of Behavioral Healthcare

Impact Behavioral Health | Indian Wells, CA

Jan 30, 2017

End of Life Option Act – The Right to Die

Beverly Hills Bar Association

Jan 12, 2017

NIMBY and New Land-Use Restrictions: What Are the Implications for Treatment Centers, and How Can They Fight Back?

National Conference on Addiction Disorders | Denver, CO

Aug 19, 2016

Issue Spotting: What Counsel Should Be Attuned to When Litigating Cases that Involve Healthcare Providers

Beverly Hills Bar Association

Aug 10, 2016

The Present and Future of Land Use Regulation within the Addiction Treatment Industry

American Addiction Treatment Association Seminar

Jul 27, 2016

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