Kenneth Homer, MD

Chief Graduate Medical Education Officer

Dr. Homer is the Chief Medical Officer of Holy Cross Hospital and an integral part of the University of Miami at Holy Cross Hospital Partnership. Prior to joining Holy Cross, Dr. Homer served as Vice Chief of Medical Staff and Chief Medical Officer of Tenet North Ridge Medical Center. Dr. Homer is an University of Miami Miller School of Medicine graduate. He completed residency at Northwestern University Medical School in Chicago, Illinois. Outside of work, Dr. Homer enjoys running, golfing, spending time with his wife, listening to good music with his sons, spending time with friends within the community.

Kartik A. Valluri, MD

Chief Medical Resident / Academic Instructor 

Dr. Valluri graduated from Internal Medicine Residency at University of Miami Palm Beach Regional Campus in 2016 and has joined University of Miami at Holy Cross Hospital as Chief Medical  Resident and Academic Instructor. He is a native South Floridian who completed his Medical School in Hyderabad, India. He focuses on developing comprehensive clinical and diagnostic skills in medical residents and cultivates new methods of teaching to foster academic growth. He enjoys film-making, creating information graphics on relevant medical topics and hopes to further the field of tele-medicine.

Howard Koch, MD

Associate Program Director

Dr. Koch is a board certified physician in Internal Medicine and Geriatric medicine. A native of South Florida, Dr. Koch received his Bachelor and Medical Degrees from the University of Miami before completing residency at the Medical University of South Carolina.  Dr. Koch has continued a strong ambulatory practice since 1979 and joined the Holy Cross Medical Group in 2011 where he became heavily involved in PA and Nursing Education. He and his wife, Bonnie, have two children together.

Stacy Rubin, MD

Associate Program Director

​​Dr. Rubin is a board certified physician in Internal Medicine.  She received her bachelor’s degree from the University of Florida and her medical degree from the University of Miami Miller School of Medicine.  She completed residency and chief residency at Jackson Memorial Hospital in Miami and received accolades for her education and teaching efforts while in residency.  Dr. Rubin joined the University of Miami/Holy Cross family in June 2016 in order to pursue her passion for Academic General Internal Medicine.  She has a special interest in patient safety and simulation as well as medical education.  A native of Broward County, she still resides in West Broward and enjoys spending time with her husband and adorable baby girl.  

Our Leadership

Angie Saint Jean, BHSA, MBA

Program Manager

Angie Saint Jean is the newest member to the UM@HCH family. Angie received a Bachelor's degree in Healthcare Administration from Florida International University and an MBA from the University Of Miami School Of Business. She has over 6 years of Graduate Medical Education experience; prior to joining UM@HCH, she worked as the Senior Program Coordinator for the Endocrine, Nephrology, and Infectious Diseases Fellowship programs at Jackson Memorial Hospital/University of Miami Miller School of Medicine. Angie has a strong interest in leadership management, mentorship and quality improvement initiatives. When Angie is not managing GME programs, she manages her son's youth football and basketball teams of her son; she works in conjunction with the coaches as the Team Mom. She also enjoys movies, Zumba classes and family time.

Yvonne Diaz, MD, FACP

Designated Institution Official  

Yvonne Diaz, MD, FACP, completed her medical degree at the Miller School in 1997 and her residency in internal medicine at UM/Jackson in 2000. She joined the faculty immediately after residency, adding the role of internal medicine associate program director in 2004. In 2012, she was named Chief Academic Officer for UHealth and Assistant Dean for Graduate Medical Education (GME). Most recently, in 2016, she was named Designated Institutional Officer for University of Miami Hospital and Clinics. Her focus throughout her career has been on enhancing the learning environment for the GME programs within the UHealth system, creating programs to support graduate medical education and mentoring young physicians. In recognition of her dedication to medical education, Dr. Diaz was awarded, in 2010, the American College of Physicians Florida Chapter “outstanding Teacher of the Year Award”.  Dr. Diaz was born in Ohio but grew up in Brazil, Venezuela, Argentina and Miami. She is fluent in Spanish and Portuguese.


Frederick K. Williams, MD, FACP

Program Director

Joan St. Onge, MD

Senior Associate Dean of Graduate Medical Education 

Dr. St. Onge graduated from Georgetown University School of Medicine and continued her training in Internal Medicine at the Georgetown University Hospital.  After her chief residency, she joined the faculty in the Division of General Internal Medicine at Georgetown, and began her career as a Clinician Educator.  She has served as Program Director in two academic institutions before coming to the University in 2008.  Dr. St. Onge has been involved in the development of the Regional Campus, working with the medical students as Integrated Medicine Clerkship Director, and Assistant Dean of Clinical Curriculum before becoming the Associate Dean for Graduate Medical Education at UMMSM.  A member of Alpha Omega Alpha, she has received a number of awards for teaching, including being named the Teacher of the Year by the ACP Florida Chapter in 2012.   Dr. St. Onge lives in the Fort Lauderdale are with her husband and two sons.  She is an avid walker, beachgoer, and cook.

Daniel Lichtstein, MD, MACP

Regional Dean of Medical Education

Dr. Lichtstein received his Bachelor of Science degree from Michigan State University in 1970 (Honors College) and his Doctor of Medicine from the State University of New York, Downstate Medical Center in 1974.  He completed his residency in Internal Medicine at Jackson Memorial Hospital in 1977 and was chief medical resident there from 1977-78.  He then entered private practice in West Palm Beach from 1978 until 1996.  In 1996, Dr. Lichtstein rejoined UMMSM and served as Program Director of the Internal Medicine Residency at Jackson Memorial from 2004-2006.  Dr. Lichtstein was elected to Mastership of the American College of Physicians in 2013.