We are a group of physicians who have been serving the Greater Long Beach area and its surrounding communities for over 30 years.

Alan Erlbaum, M.D.
Alan Erlbaum, M.D.
Alan Erlbaum, M.D.

Dr. Erlbaum received his medical degree from the University of California Los Angeles and finished his Internal Medicine Residency at USC Medical Center. He completed the Nephrology Fellowship training at UCLA Medical Center. He is board-certified in Internal Medicine and Nephrology. He is also on the volunteer faculty at Saint Mary Medical Center's Internal Medicine residency program as well as a team physician for the University of Southern California.

Karen Zoller, M.D.
Karen Zoller, M.D.

Dr. Zoller received her medical degree from the University of California Los Angeles and finished her Internal Medicine Residency and Nephrology Fellowship training at Harbor-UCLA Medical Center. She is board-certified in Internal Medicine and Nephrology. She is also on the volunteer faculty at Harbor-UCLA Medical Center's nephrology fellowship program. She is also member of Memorialcare's electronic medical records committee.

Karen Zoller, M.D.
Essam Maasarani, M.D.
Essam Maasarani, M.D.
Essam Maasarani, M.D.

Dr. Maasarani received his degree from Alexandria University, Egypt and finished his Internal Medicine Residency in Saint John’s Episcopal Medical Center. He completed the Nephrology Fellowship training at Harbor-UCLA Medical Center. He is board-certified in Internal Medicine and Nephrology. He is also on the volunteer faculty at Saint Mary Medical Center's Internal Medicine residency program.

John Hsieh, M.D.
John Hsieh, M.D.

Dr. Hsieh received his medical degree from Tufts University and finished his Internal Medicine Residency at University of California Irvine Medical Center. His Nephrology Fellowship training was completed at Harbor-UCLA Medical Center. He is board-certified in Internal Medicine and Nephrology. He is also on the volunteer faculty at University of California Irvine's Internal Medicine residency program as well as a guest lecturer for Memorial Family Medicine residency program and Saint Mary Internal Medicine residency program.

John Hsieh, M.D.
Alice Park, M.D.
Alice Park, M.D.
Alice Park, M.D.

Dr. Park received her medical degree from Saint Louis University and finished her Internal Medicine Residency at University of California Irvine Medical Center. She completed the Nephrology Fellowship training at University of California Irvine Medical Center. She is board-certified in Internal Medicine and Nephrology. She is also on the volunteer faculty at Saint Mary Medical Center's Internal Medicine residency program.