Job Title: Part-Time Medical Biller. Location. La Mesa, California – San Diego County. Schedule. Part-Time | Operational hours: 9:00 AM – 5:00 PM. About Us. At. Grossmont Pediatrics. our mission is to provide. family-focused, individualized care. for every child. We are a small, independent pediatric practice located in. La Mesa, CA. proudly serving a diverse population of. Commercial HMO, PPO, Tricare, and Medi-Cal. patients. Through our strong ...