Palomar Medical Group
  Our Specialists


John J. Lilley, M.D. is a Nephrologist with Palomar Medical Group, specializing in the treatment of Kidney Disease and Hypertension. He is board certified in both Internal Medicine and Nephrology and currently is the Medical Director of the Hemodialysis Facility in Escondido, California.




Robert M. Stein M.D., F.A.C.C. is a cardiologist in the Palomar Medical Group. He is board-certified in internal medicine and in cardiovascular diseases. In addition to his private practice, Dr. Stein was Chief of Staff at Palomar Medical Center, and has been Medical Director for Cardiovascular Services at Palomar Pomerado Health for a number of years. He also serves on the board of directors of the Greater San Diego Chapter of the American Heart Association, and is President-Elect of the board.




Mark Shapiro, M.D. is an Internal Medicine specialist who is also board-certified in Nephrology, the study of kidney related disorders.Following his undergraduate training at UCLA, Dr. Shapiro earned his medical degree at the University of Pittsburgh Medical School, and served an internship and residency at UC San Diego (where he was also Chief Resident).  While at UCSD, he completed a Nephrology Fellowship.  Today, his association with UCSD continues with service as Assistant Professor of Medicine.




Joshua K. Greenstein M.D. joined Palomar Medical Group as a board-certified specialist in Nephrology and Internal Medicine. Dr. Greenstein earned his BA in physics from Columbia University in New York in 1992 and graduated from University of California Los Angeles Medical School in 1997. In 2000, he completed his Internal Medicine residency at UCLA and a year later, took a fellowship in Nephrology at Stanford University School of Medicine. While at Stanford, Dr. Greenstein's research interests focused on improving nutrition in dialysis patients.




Dr. Osman Khawar, M.D., M.P.H. is board-certified in Internal Medicine and specializes in peritoneal dialysis. A graduate of Glasgow University Medical School in Glasgow, Scotland, Dr. Khawar completed his Internal Medicine residency program at St. Mary Medical Center in Long Beach, California and received his Nephrology Fellowship from Harbor UCLA. Dr. Khawar also has a Master of Public Health from Johns Hopkins School of Public Health. He has done extensive research and published studies in the area of peritoneal dialysis and brings his experience performing and reading ultrasounds and biopsies to Palomar Medical Group.