About Us

Providers' Bios

biernbaum_Web.jpgROBERT BIERNBAUM, D.O.

Chief Medical Officer, Board Certified in Emergency Medicine

Robert “Rob” Biernbaum, D.O. holds a Master’s degree in Epidemiology from the State University of New York at Buffalo and a Doctorate of Osteopathy from the University of New England.  He completed his Residency in Emergency Medicine at Genesys Regional Medical Center.

In his vital role as Chief Medical Officer, Biernbaum oversees Trillium Health’s expansion as we provide new services, barrier-free access to medical care & supportive services while increasing access to populations with crucial health care needs. His expertise in emergency and trauma-induced care will greatly benefit the patients Trillium Health serves.

Robert joined Trillium from MultiCare Health System, an organization with a fast-paced trauma center, four community hospitals, and many neighborhood clinics based in Tacoma, Washington. Prior to MultiCare, Biernbaum was Rochester Regional Health System’s chief architect for all Epic solutions and in charge of informatics for five hospitals and more than 100 ambulatory sites. He also was the executive responsible for quality measures and meaningful use.

A native Rochesterian with roots in Pittsford & Victor, his expertise will be invaluable to Trillium Health, as the organization continues to focus on the highest quality and affordable healthcare.


WILLIAM M. VALENTI, M.D.William M. Valenti

Senior Vice President for Strategic Advancement, Chief of Innovation, Co-Founder, and Staff Physician

Dr. Valenti is a graduate of the Medical College of Wisconsin and co-founded Community Health Network in 1989. He is Clinical Associate Professor of Medicine at the University of Rochester School of Medicine and Dentistry and completed his Infectious Diseases training at the University of Rochester. He is a fellow of the Infectious Diseases Society of America. He has been active in HIV-related activities since the early 1980s and is chair of the Infectious Diseases Committee of the Medical Society of the State of New York and is a member of New York State's Task Force to End the HIV Epidemic by 2020.

He has published more than 150 peer-reviewed articles, book chapters and scientific abstracts on HIV medical care, infectious diseases and health care epidemiology and infection control.

As Chief of Innovation, Dr. Valenti oversees programs to End the HIV Epidemic, including Pre-exposure HIV Prophylaxis (PrEP), LGBTQ Health and the MOCHA Centers.


MICHAEL D. MANCENIDO, D.O.Michael D. Mancenido
Staff Physician

Dr. Mancenido joined the agency in December 2006 as a full-time Spanish-speaking staff physician. After graduating from the University of New England College of Osteopathic Medicine in June 2001, Dr. Mancenido completed both a residency in Internal Medicine and fellowship in Infectious Diseases at the University of Massachusetts Medical School. He is Board Certified in Internal Medicine and Infectious Diseases and is certified as an HIV specialist.

His commitment to increasing health care accessibility for the underserved has led him to pursue several volunteer opportunities. In 2005 Dr. Mancenido spent several weeks in the Dominican Republic helping to create a satellite HIV clinic. Most recently, Dr. Mancenido spent six weeks at the Dessie Regional Referral Hospital in Ethiopia, training local HIV healthcare providers, and offering HIV prevention education to the community.


William Schaefer

WILLIAM SCHAEFER, M.S. RPA-C, AAHIVS
Physician Assistant

Mr. Schaefer has been with Trillium Health since 2008.  Mr. Schaefer specializes in transgender health, LGB health, HIV specialty care and primary care, practicing under the direction of Dr. William Valenti.  He is the Director of Advance Practice Providers (Physician Assistants and Nurse Practitioners) and the Director of Trillium’s Transgender Center of Excellence. 

Mr. Schaefer received his Masters of Science in Physician Assistant Studies at Towson University in Baltimore, MD in 2015 after receiving his Bachelors of Arts at the State University of New York at Buffalo in 2007. He was previously employed as a physician assistant at Chase Brexton Health Care in Baltimore, MD.


Shani Wilson, PA-C
Board-certified Physician Assistant (NCCPA)

Shani Wilson, PA-C, is a Board-certified Physician Assistant (NCCPA), with a Bachelor’s of Science Degree from Rochester Institute of Technology. She has been with Trillium Health since 2016. Shani’s areas of expertise and interest are Primary Care, Suboxone Treatment, LGBTQ Health, sexual health, minority health disparities and vaccine preventable diseases. Since 2017, she has served as co-chair of Trillium Health's President's Council on Diversity and Inclusiveness.


Erin Grindle, PA-C

Board-certified Physician Assistant (NCCPA)

• Primary Care

• Suboxone Treatment

• LGBTQ Health Care