A Message to Our Community: Changes to our visitation policy are in effect until further notice.

Recent News

Irvine school nurses, staff learn Stop the Bleed techniques to respond in mass-casualty situation

Irvine school nurses and athletic trainers on Tuesday, Jan. 30, learned simple techniques that could save lives in a shooting or other ...

Read More

Families anticipate exciting community blessing of surgical center

A community is as strong as its hospital, and with recent investments into Covenant Health Plainview, it’s evident that to our friends ...

Read More

Severe Flu Season Tightens Its Grip on U.S.

Americans are being hit with one of the worst flu seasons in years, with misery now widespread across 46 states, health officials say. In ...

Read More

About St. Joseph Health

SJH provides a full range of care facilities including 16 acute care hospitals, home health agencies, hospice care, outpatient services, skilled nursing facilities, community clinics and physician groups. All of our hospital and home health entities are accredited by the Joint Commission. In our award-winning facilities, SJH maintains a "continuum of care," matched to the diverse needs of the urban centers, smaller cities and rural communities who depend on us every day.

Mary M. Koumas, DO

  • Family Medicine
Additional Language Spoken
24401 Muirlands Boulevard
Suite A
Lake Forest, CA 92630

Primary Office

24401 Muirlands Boulevard
Suite A
Lake Forest, CA 92630
Get Directions
(949) 770-1950
(949) 770-8599
Mon 9 a.m. - 6 p.m., Tue 9 a.m. - 6 p.m., Wed 9 a.m. - 6 p.m., Thu 9 a.m. - 6 am. Fri 9 a.m. - 6 am. Sat

More Information

  • Meet The Doctor

    Specialties & Education

    Primary Specialties
    • Family Medicine
    Education & Training
    • Medical School
      Kirksville College of Osteopathic Medicine
    • Internship
      Doctors Hospital of Columbus - 1979
    Areas of Interest

    Family Medicine

  • Biography


    Dr. Mary Koumas is a family medicine doctor in Lake Forest, California and is affiliated with multiple hospitals in the area, including Mission Hospitals, Mission Viejo and Laguna Beach. She received her medical degree from A.T. Still University Kirksville College of Osteopathic Medicine and has been in practice for more than 20 years.
    American Osteopathic Board of Family Physicians