ABOUT THE
PRACTICE
PEDIATRIC ASSOCIATES
WHY PEDIATRIC ASSOCIATES?
Welcome to Pediatric Associates of Stockton. We are proud to say that we have been doing business in Stockton since 1949. The practice was started by Dr. Frank Ruhstaller in a small office down on Harding Way. The practice grew and grew over time as the people of Stockton learned of his medical expertise. Because of this growth, he added partners who are still with the practice to this day.
All providers and staff of Pediatric Associates of Stockton appreciate that you have chosen us to provide health care for your child. Our goal is to provide the highest quality, friendliest, and most efficient medical care for your child that is possible.
We provide medical care for children from birth through age 19. Our focus is on prevention and patient/parent education in collaboration with your family to promote good health and prevent disease and injury.
Because we are a group practice, you will have an opportunity to see each of the physicians and nurse practitioners in our office. Our physicians have the utmost confidence in our nurse practitioners for their expertise with pediatric patients. All physicians and nurse practitioners work very closely together to provide the best possible pediatric care in San Joaquin County.
OUR EXPERT PHYSICIANS
We are a four physician, three nurse practitioner practice which concentrates on providing the highest quality, friendliest, and most efficient pediatric care in San Joaquin County. Each of our physicians is certified by the American Board of Pediatrics and are members of the American Academy of Pediatrics.
Dr. Steven Billigmeier
Steven Billigmeier, MD, FAAP (Dr. “B”) is a San Joaquin County native, growing up in Linden, CA. He attended Stanford University in Stanford, CA, where he completed his Bachelor of Science degree in Biological Sciences, receiving the Award of Excellence in Teaching from the Department of Biological Sciences in 1989.
He continued his studies at the University of California, Davis of Medicine in Sacramento, CA, where he was inducted into the Alpha Omega Alpha Medical Honor Society in 1992. In 1993, he received his Medical Degree and was honored with the Award for Excellence in Pediatrics by the U.C. Davis School of Medicine.
After completing his residency at the University of California, Davis Medical Center in Sacramento, CA in 1996, Dr. “B” began working with Dr. Cahill at her pediatric office in Stockton. Together, they founded Pediatric Associates of Stockton in 1998.
Dr. “B” married his Linden High School sweetheart, Jimi. Dr. “B” and Jimi have five children. They currently live in Linden, where he is highly active in many community and school events and activities.
Dr. “B” is a board-certified Pediatrician by the American Board of Pediatrics, making him a specialist in the care and treatment of infants, children, and adolescents. He has active hospital privileges exclusively at St. Joseph’s Medical Center, where he was Chief of Pediatrics for six years.
He is a current member of the American Academy of Pediatrics, the California Medical Association, and the San Joaquin Medical Society. In 2015, Dr. “B” received the honor of being selected to receive the Young Physician of the Year award by the San Joaquin Medical Society, not only for his exemplary care, but also for his active involvement with the community.
In his spare time, Dr. “B” enjoys spending time with his family, helping his community, traveling, and playing with his grandchildren.
Dr. Carol Cahill
Carol Cahill, MD, FAAP (DR. “C”) is originally from Southern California and attended Cornell University in Ithaca, NY, completing a double major with a Bachelor of Science degree in Neurobiology and Asian Studies. She continued her education at the University of Southern California where she became a Ph.D. candidate for the Department of Anatomy.
She then attended USC’s, Keck School of Medicine, earning her Doctor of Medicine degree in 1984 all while having four children. During her years in medical school, she was a teaching assistant and tutor to other medical students. It was while in medical school that she realized her passion for ensuring the care and well-being of children and went on to complete her pediatric residency training at the University of California, Davis at the Davis Medical Center in Sacramento, CA.
During her residency, she married Dr. Edward Cahill, a Stockton orthopedic surgeon. They have lived in Stockton since 1988 and have four grown children, three of which are physicians.
Dr. Cahill is board certified Pediatrician with the American Board of Pediatrics which she identifies her as a specialist in the care and treatment of infants, children, and adolescents. She is on staff at St. Joseph’s Medical Center. Dr. Cahill currently serves as a preceptor to nurse practitioner students during their pediatric rotation.
She is a member of the American Academy of Pediatrics, the California Medical Association, and the San Joaquin Medical Society. Dr. Cahill is a founding partner of Pediatric Associates of Stockton.
In her spare time, Dr. Cahill enjoys spending time with her family (especially her eleven grandchildren), swimming, hiking, gardening, travelling, and taking too many pictures.
Dr. Linda Sakimura
Linda Sakimura, MD, FAAP (“Dr. S”) began practicing pediatrics in Stockton in 1999, and became a partner in Pediatric Associates of Stockton in 2001. She is a southern California native and graduated cum laude from Harvard University in Cambridge, MA in 1991 with a BA in English and American Literature and Languages.
Dr. “S” continued her schooling at the University of California, Los Angeles where she received her medical degree in 1996.
Dr. Sakimura did research at the California Institute of Technology in Pasadena, CA from 1988-1989, and at the National Institutes of Health/National Institute of Child Health and Human Development in 1990 and in the Department of Dermatology at UCLA from 1992-1993. She worked at the National Institute of Leprosy in Tokyo, Japan in 1993, and at the NIH/National Institutes of Allergy and Infectious Disease, Howard Hughes Medical Institute/NIH Research Program from 1993-1994.
After medical school, Dr. “S” did her pediatric residency at the Children’s Hospital Medical Center of Northern California in Oakland, CA before moving to Stockton and coming to work with Dr. Cahill and Dr. Billigmeier. She is board certified by the American Board of Pediatrics and an active member of the California Medical Association as well as the San Joaquin Medical Society. She has hospital privileges exclusively at St. Joseph’s Medical Center.
Dr. “S” is married to Dr. Alan Kawaguchi, an orthopedic surgeon in Stockton. They have twin sons, Alex and Andrew. She loves spending her spare time with her family, skiing, reading books and rooting for the Sacramento Kings.
Dr. Erica Waters
Erica R. Waters, MD FAAP (Dr. “W”) is a native of New York. She completed her Bachelor of Arts Degree in Psychology in June of 1994 at Princeton University, Princeton, NJ., where she graduated Magna Cum Laude and was chosen All-Ivy, first team Track and Field/Athletic achievement, and All-Ivy Cross Country/Academic and Athletic achievement.
She obtained her Medical degree from Vanderbilt University School of Medicine in Nashville, TN in 1998. At Vanderbilt she was awarded The Kaufman Prize in Medicine for qualities of humanness, dedication, and unselfish service in the study of medicine. She also was honored by being inducted into the Alpha Omega Alpha Medical Society.
Upon graduation from Vanderbilt, she continued her education by completing her residency program at Johns Hopkins Hospital in Baltimore, MD in 2001.
While at Vanderbilt, Dr. “W” met her husband, Richard Waters, MD, a Stockton native and Cardiologist. They have two children, Ella and Reed and an amazing dog, Midnight.
After Mr. Dr. Waters finished his cardiology training, they decided to relocate to the West Coast, settle in his hometown, and practice medicine in their chosen specialties. So, in 2005, Dr. Waters joined Pediatric Associates of Stockton and became a partner in 2007.
Dr. “W” is Board Certified in pediatrics by the American Board of Pediatrics and is a Fellow of the American Academy of Pediatrics, The California Medical Association, and the San Joaquin County Medical Society. Dr. Waters has active hospital privileges exclusively at St. Joseph’s Medical Center.
Dr. “W” interests include spending time with her family, running, hiking, leisure reading, and gardening.
Dr. Thomas Howell
Dr. Howell, MD, FAAP (Dr. “H”) grew up in Stockton, CA and attended the University of the Pacific, graduating in 2004 with a Bachelor of Arts degree in Mathematics. He studied medicine at Loma Linda University in Southern California, receiving his medical degree in 2008, and completed his residency in Pediatrics at Loma Linda University Children’s Hospital in 2011. After residency, Dr. Howell returned to Northern California, where he worked as a pediatrician in Elk Grove. He then spent a few years working in Long Beach, CA before returning to Elk Grove in 2019. He then joined Pediatric Associates of Stockton in 2026. He currently lives in Stockton with his wife and son. Dr. Howell is board certified by the American Board of Pediatrics and is enthusiastic about preventative care and helping children grow up healthy from infancy to adolescence. He is a Fellow of the American Academy of Pediatrics. In his spare time, Dr. Howell enjoys spending time with his family, fencing and playing bass guitar.