Castro Valley Office

Anna Aggarwal, MD
Gene-Yuan Chang, MD
Kathryn Welty, MD

20055 Lake Chabot Road, Suite 230
Castro Valley, CA 94546
Phone (510) 881-1490
Fax (510) 889-5806
View Map

Office hours:
Monday to Friday
9am – 5pm

Free parking on site


Castro Valley Office

Anna Aggarwal, MD

Medical School: Howard University
Residency: Alameda County Hospital (UCSF Affiliated)
Fellowship: University of California, Davis
Board Certifications: Internal Medicine and Nephrology
Languages: Hindi, basic Russian
Started Practice: 2008
Offices: Castro Valley

Raised in Maryland, Dr. Aggarwal received a scholarship to attend the University of Maryland. She did research at the National Institutes of Health while attending college and after graduation. After her nephrology fellowship, she remained on the UC Davis Kidney Transplant staff for two years before joining Chabot Nephrology in 2008.

She has special interests in kidney transplantation and hypertension. She also cares for patients with chronic kidney disease, including patients needing hemodialysis and peritoneal dialysis. Given her experience at a university transplant center, she offers her special skills in helping patients navigate the process of transplant referral, as well as evaluation of potential donors.
She also follows patients after transplantation.

"I am fully committed to patient education and feel that there should be a partnership between the physician and patient. I also feel a physician can guide a patient toward better health, but it is the patient that must make the day to day life changes that ultimately will result in better health.”

Dr. Aggarwal is married and has two children. In her free time she loves to cook and coach soccer.  She also enjoys photography.

Castro Valley Office

Gene-Yuan Chang, MD

Medical School: Boston University School of Medicine
Residency: Montefiore Medical Center-Albert Einstein College of Medicine
Fellowship: University of California, San Francisco
Board Certifications: Internal Medicine
Special Interests in Nephrology: hypertension, diabetic kidney disease
Languages: Mandarin (conversational)
Offices: Castro Valley

Dr Chang was born in Taiwan before spending most of his childhood in Boston. He attended Boston University and received his bachelors degree in biochemistry and molecular biology with a minor in sociology, then stayed at BU to pursue his medical degree. He then moved to the Bronx for internal medicine residency training because of his interest in treating underserved patient populations. He was finally able to realize his dream of living in California when he was accepted for nephrology fellowship at the University of California, San Francisco. His ability to communicate and educate both patients and other medical providers earned him the respect of the UCSF Internal Medicine Department in his first year of training as they named him the nephrology fellow of the year. While he initially planned on becoming a physician-scientist, Dr Chang ultimately realized that his true interest in medicine was in direct patient care, and so he left a career in laboratory science to join Chabot Nephrology as a full-time clinician.

Castro Valley Office

Kathryn Welty, MD

Medical School: Vanderbilt University School of Medicine
Residency: University of Washington
Fellowship: University of Washington
Board Certifications: Internal Medicine, Nephrology
Started Practice: 2013
Offices: Castro Valley

Kathryn (Kay) Welty, MD was born in Boston and raised in southern Massachusetts. She attended Brown University where she received a Bachelors of Science degree in Neuroscience.   She graduated from Vanderbilt University School of Medicine and completed her Internal Medicine training at the University of Washington, where she also served as Chief Resident at the Seattle Puget Sound VA Medical Center. She remained at the University of Washington for Nephrology fellowship, which she completed in 2013. She was also selected and completed the Teaching Scholars certificate program at UW during her fellowship.  Dr. Welty is board certified in internal medicine and nephrology by the American Board of Internal Medicine.

Dr. Welty lives in Oakland with her husband, daughter, and their dog Zoey. Her interests include cooking, hiking, music of all types, and enjoying the outdoors with her family.