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Dennis S. Diaz

DiazDennis
Partner
T213.633.6876
F213.633.6899
Dennis Diaz is a health care regulatory and transactional lawyer. For over 25 years, he has represented a wide range of health care providers, including multi-hospital systems, community hospitals, physician-hospital organizations, ambulatory surgery centers, and medical groups, in California and nationally. Dennis focuses his practice on regulatory and compliance matters, fraud and abuse, provider transactions including hospital-physician alignment and joint ventures, provider operations, and billing and payment issues. He regularly advises and defends providers against government enforcement actions and in investigations involving health care regulatory issues, and has served as lead counsel in structuring hospital-physician integrated delivery organizations, including accountable care organizations and medical foundations, and ambulatory surgery centers. Dennis also acts as outside general counsel to hospitals and medical groups.

Practice Highlights
  • Defending actions brought by the Department of Health and Human Services (DHHS), the Office of Inspector General (OIG), the Centers for Medicare and Medicaid Services (CMS), the California Department of Health Care Services (DHCS), the California Department of Public Health (CDPH), and local governmental authorities
  • Internal health care regulatory and compliance matters, including audits and investigations, corrective actions, refunds, and disclosure to the government
  • Structuring and negotiating hospital-physician contracts and joint ventures, including strategies for hospital-physician alignment and integration, and forming ambulatory surgery centers  
  • Federal and state physician self-referral (Stark and PORA), anti-kickback, and fraud and abuse issues in connection with physician contracts and provider operations
  • Billing and reimbursement disputes with governmental and commercial payors, including the Medicare and Medicaid programs
  • Conducting due diligence of health care regulatory and compliance affairs on behalf of buyers, investors, lenders and sellers in acquisitions and financing transactions
  • General counsel to community hospitals and medical groups

Representative Experience

Audit and internal regulatory and compliance review for 12-hospital system

Internal audit and compliance review of all financial relationships with physicians to evaluate and recommend corrective action for compliance with Stark and anti-kickback laws.

Audit and internal regulatory and compliance review for community hospital

Internal audit and compliance review of all financial relationships with physicians to evaluate and recommend corrective action for compliance with Stark and anti-kickback laws.

Audit and internal regulatory and compliance review for two-hospital system

Internal audit and compliance review of all financial relationships with physicians to evaluate and recommend corrective action for compliance with Stark and anti-kickback laws.

Compliance and regulatory counsel for California hospitals

Primary outside health care regulatory and compliance counsel for multiple California hospitals.

Health care regulatory and compliance review for multi-hospital system

Due diligence and health care regulatory review and representation of a multi-hospital system in a $100 million hospital asset acquisition.

Hospital homeless patient discharge litigation for Southern California hospital

Resolution of high-profile lawsuits brought by the Los Angeles City Attorney and patients against a Southern California hospital in connection with homeless patient discharges. Defense of patient discharge litigation against a community hospital.

Reimbursement and billing disputes for large medical groups

Representation of multiple medical groups in multimillion-dollar billing and reimbursement disputes with major health plans.

Structuring of clinics for multiple hospital systems; community hospitals

Advice in the structuring of hospital-physician clinic models for multiple hospital systems and community hospitals.

Additional Qualifications

  • Adjunct Professor of Law, Health Law, University of Southern California Gould School of Law
  • Adjunct Professor of Law, Health Law, Loyola University School of Law
  • Lecturer, Health Care Law for Managers and Entrepreneurs, University of California, Irvine - Executive MBA Program
  • Partner, Sonnenschein Nath & Rosenthal LLP
  • Staff Counsel, Office of General Counsel, U.S. Department of Health and Human Services, Washington, D.C.

Professional & Community Activities

  • American Health Lawyers Association

Professional Recognition

  • Named one of "America's Leading Lawyers for Business" in Healthcare (California) by Chambers USA, 2010-2014 
  • Named one of the country's 12 "Outstanding Hospital Lawyers" by Nightingale's Healthcare News, 2007
  • Named one of the "Best Lawyers in America" in Health Care Law by Best Lawyers, 2010-present
  • Selected to, "Top Rated Lawyers Guide to Health Care Law," Corporate Counsel, 2012, 2013 
  • Highest rating (AV) by peers – Martindale-Hubbell Legal Rating Service