Diane Ung is a partner and health care business lawyer with Foley & Lardner LLP. Diane focuses her practice on federal and state health care legislation and payment issues arising under government programs such as Medicare and Medicaid. Her practice includes regulatory, legislative, health care and business matters for public agency clients. Diane has specific experience in structuring Medicaid financing for safety net providers in the context of disproportionate share hospital payment programs and under federal Medicaid demonstrations authorized under Section 1115 of the Social Security Act. Diane is a member of the firm's Health Care Industry Team.

Diane has represented county health departments, county managed care organizations, public hospital systems, and various large publicly operated teaching hospitals. She has helped clients evaluate and develop demonstration projects that implement innovative programs for Medicaid beneficiaries. Diane has drafted legislation regarding the Medicaid program, including statutes involving disproportionate share hospital payment adjustment systems, and has advised clients regarding Medicaid program audits conducted by the DHHS Office of the Inspector General. She has counseled clients in connection with the restructuring of public health agencies and the evaluation of public/private partnerships, including the transfer of a public hospital to a nonprofit entity. Diane also has advised clients on matters involving federally qualified health centers, and the 340B drug pricing program.

Prior to beginning her legal career, Diane spent five years in facility health planning and health services research for a major health maintenance organization.


  • Recognized in Chambers USA: America's Leading Lawyers for Business in the practice area of healthcare (2021)
  • Recognized by Southern California Super Lawyers® since 2014
  • Selected by her peers for inclusion in The Best Lawyers in America© since 2013 in the field of Health Care Law


Diane is a graduate of Loyola Law School, Los Angeles (J.D., 1993), where she was Order of the Coif; the University of California, Los Angeles, School of Public Health (M.S.P.H., 1987), where she specialized in health planning and policy analysis; and Pomona College (B.A., 1985).

Professional Memberships

Diane is a member of the American Health Lawyers Association, the California Society for Healthcare Attorneys, and the Los Angeles County Bar Association for which she previously served as chair of the Healthcare Law Section. She serves on the board of directors of the Women in Health Administration of Southern California, serving as its president in 2007 and 2008.


  • California (1993)
  • District of Columbia (1996)