Fred Bauermeister stopped answering phone calls, pooling donations and bringing medical help to the underserved — something the local healthcare community feared most.

Bauermeister walked out the door in May, taking with him 37 years of knowledge and what many consider to be the heart and soul of the Free Clinic of Simi Valley.

But his absence was just a test.

On Tuesday, one day after his 60th birthday, Bauermeister returned as executive director, following a grant-sponsored three-month sabbatical meant to give him a breather while seeing how the clinic would run without him.

"For good or bad, being there that much can be a bad thing," Bauermeister said. "We had to see if all this work over the years isn't going to fail if I had to leave."

As part of the grant's conditions, he wasn't allowed to have any contact with the healthcare facility he watched grow into one of the most comprehensive free clinics in the state, according to local health officials.

When someone becomes indispensable to a nonprofit's operation, it's time to examine the vulnerable spots, he said.

The California Wellness Foundation awarded a $35,000 grant to cover Bauermeister's paid time off, as well as the added costs for staff to handle extra responsibilities. The purpose was also to groom Bauermeister's possible future replacement.

Enter Adriana Trujillo, 33, a longtime clinic advocate who's been filling in for Bauermeister since he left May 3. She is a registered nurse who also has been the clinic's top administrator since January. Last year, she completed a residency program at Kaiser Permanente in Woodland Hills.

Trujillo sat in Bauermeister's office recently among the awards he and the clinic have received over the decades. Above her head hung the sabbatical certificate, which afforded her a chance to see what it was like to be at the helm.

"He's given his life to this place. He's a role model for me," she said.

The bilingual Trujillo walked through the door about five years ago as a volunteer and continued to help out during her residency, where she pulled 30-hour shifts at Kaiser Permanente. She still works there to supplement her income.

The clinic is a clean, one-story office at Tapo and Industrial streets. Its yearly budget hovers around $250,000, Bauermeister said. The clinic depends entirely on donations and receives no government funding.

Bauermeister started the Free Clinic in 1971 and has overseen it ever since, with a staff of volunteers and part-timers. Over the years, it has offered medical and dental care, legal assistance and counseling to more than 70,000 adults and children.

On a recent afternoon, about 25 people waited in line to make an appointment. Trujillo said there is also a waiting list of about 500 people for services that aren't available on a daily basis.

The clinic is open more hours than ever, with additional doctors and dentists who have signed on to help for free. But the demand continues to rise, Trujillo said.

"The need for service has easily doubled from last year," she said.

The clinic's rotation of volunteer doctors and doctors-in-residence from Kaiser Permanente handle the full range of healthcare — from health maintenance to chronic illnesses like diabetes and hypertension to follow-ups from emergency room visits.

Trujillo sees a new crop of clients. They are no longer only the homeless, the unemployed and working poor. They now include the middle class, working professionals. And since Medi-Cal's funding went dry because of the budget impasse last month, more patients are coming to the clinic rather than a hospital.

Years ago, Trujillo was also a client — she needed medical treatment and didn't have enough insurance for certain medications.

In June, the Free Clinic treated 794 patients, up from 460 patients in the same month last year.

Trujillo has learned to play triage at the front counter — answering the perpetually ringing phone, tending to patients as a nurse, talking with clients. She's also in charge of keeping the donations coming in and has organized the next big fundraiser in October.

Dennis Benton, former president of the Free Clinic's board of directors and the current executive director for Kaiser Permanente, said Trujillo is a hard worker with a "great deal of common sense."

"She is just completely dedicated to the mission of the clinic. She believes it down to her soul," Benton said. "Just like Fred, she would do anything for the clinic."

He also said she has learned how to delegate since trying to fill Bauermeister's shoes.

"If something happened to me and all of a sudden I had to leave, now I know, OK, you can do this without me," Bauermeister said.

The Free Clinic at 2060 Tapo St. is open from 5 to 8 p.m. Monday through Friday. It is staffed by volunteer physicians, nurses, attorneys, paralegals and counselors. Call 522-FREE (3733) for more information.