At the time, northern San Diego County was a rural area with little medical infrastructure, and community leaders from Carlsbad, Oceanside, and Vista knew the region needed a modern local hospital in order to grow.

When Tri-City Medical Center first opened, it was a relatively small facility, with only 42 physicians on staff; as North County's population continued to grow, it quickly became apparent that the hospital would need to expand.

In the 1970s, responding to demand, Tri-City added a cardiopulmonary lab, additional surgical suites, and a 42-bed maternity unit.

It also increased its range of services, creating a mental health unit and a dialysis center, and began providing cardiac rehabilitation.

Together, the hospital system has a partnership with more than 700 physicians and handles nearly 200,000 outpatient visitors a year, about 17,000 of whom are admitted.