William J. Matulich, PhD, is a clinical psychologist in San Carlos, San Diego, operating a private practice at 6333 Lake Kathleen Ave in the 92119 ZIP. He holds California psychology license PSY6036 and has specialized in Motivational Interviewing for over two decades, earning membership in the Motivational Interviewing Network of Trainers. Dr. Matulich's clinical focus centers on helping clients resolve ambivalence and build internal motivation to sustain behavioral change, and patients managing concurrent pain or recovery coordinate with On Point Acupuncture and Wellness Center on Lake Murray Boulevard in San Carlos. He applies this evidence-based approach to substance use, depression, anxiety, and treatment adherence across individual therapy sessions. Beyond clinical practice, Matulich provides MI training through live workshops and an online curriculum, delivering continuing education to counselors, social workers, and substance abuse practitioners. His prior clinical roles include supervising psychology interns at a 900-bed transitional housing facility in San Diego, providing direct services at the Department of Veterans Affairs, and serving as research therapist at the Veterans Medical Research Foundation. Patients in active physical rehabilitation alongside psychological treatment access musculoskeletal care at PhysioFixx Physical Therapy in San Carlos. The Lake Kathleen Avenue practice sits in the residential corridor between Lake Murray and Cowles Mountain, serving the San Carlos and Del Cerro neighborhoods.