UCLA Mattel Children's Hospital (MCH) at Ronald Reagan UCLA Medical Center is a nationally ranked pediatric acute care children's hospital located in Los Angeles, California. The hospital has 156 pediatric beds, is affiliated with the University of California, Los Angeles David Geffen School of Medicine, and is a member of UCLA Health. The hospital provides comprehensive pediatric specialties and subspecialties to pediatric patients aged 0–21 throughout California. Mattel Children's also sometimes treats adults that require pediatric care. UCLA Mattel Children's Hospital features an ACS verified pediatric level 1 trauma center. The UCLA Mattel Children's Hospital is located on the third and fifth floors of the newly constructed Ronald Reagan UCLA Medical Center.

The University of California, Los Angeles School of Medicine, also known as the David Geffen School of Medicine at UCLA (DGSOM), is an accredited medical school located in Los Angeles, California, United States. Founded in 1951, it is the second medical school in the University of California system, after the UCSF School of Medicine. The school was renamed in 2001 in honor of media mogul David Geffen who donated $200 million in unrestricted funds.