Chestnut Hill Hospital's Family Practice Residency program has graduated more than 180 residents since its inception in 1974. Many of the program's alumni are now practicing medicine in the Philadelphia metropolitan area, while other graduates practice throughout the country in such places as California, Florida, Hawaii and even Bermuda. All graduating residents have passed the certification boards on the first attempt.

The Hospital has formed physician networks to help facilitate our move toward an integrated health care system focusing on primary care and covered lives. There is ample opportunity for graduates to stay and practice in the community.

Third Year

Juyeon Lee, M.D. , Co-Chief


I have traveled quite a bit throughout my life. I was born in Seattle, but spent most of my childhood in Seoul, attending Korean schools. Then I returned to Seattle for my undergraduate education and majored in Accounting at University of Washington. Prior to attending medical school at the Medical College of Wisconsin in Milwaukee, I lived in Manhattan for a few years working as an accountant. I am drawn to the value of providing continuous and comprehensive care in Family Medicine along with the meaningfulness of making a difference in people's lives in acute and chronic settings. Based on my business background, I'm also interested in areas like quality improvement, management, and finance within healthcare. During my interview at Chestnut Hill, I was impressed by the welcoming and supportive atmosphere, the unique setting of a community hospital with a suburban feel yet close proximity to a major city, and strong focus on providing efficient and effective quality care. I am looking forward to the next chapter of my life in Philadelphia, training at Chestnut Hill and enjoying other things life has to offer including cooking, dancing, biking, and spending time with family and friends.

You can email Dr. Lee at

Rachelle Nelson, M.D.


I come to Philadelphia from Rochester, New York were I have spent the majority of my younger years under the snow. I earned a Bachelors in biology at SUNY Geneseo (best pizza in the universe) and completed medical school at SUNY Upstate in Syracuse. I am excited and honored to have the opportunity join this program for my training. My current interests involve working with the underserved and palliative care. In my free time, I invent new ways to get vegetables into my squirrelly toddler and discuss the upcoming zombie apocalypse with my nerdy husband (ad nauseum). While I sometimes miss the snow and pizza of Upstate NY, I am enjoying every bit of living in Philadelphia (home of the best taco trucks in the universe).


Ariel Postone, M.D.


was born and raised in Berkeley, CA and attended the Residential College at the University of Michigan, Ann Arbor. In college, I participated in an intensive language program and studied abroad in Brazil with SIT's public health and social justice program. Obtaining an interdisciplinary social science major enabled me to study the human condition through a variety of lenses. After college, I pursued my interests in public health and completed a post-baccalaureate at Mills College in Oakland, CA while simultaneously volunteering at a clinic for day laborers and at the Emergency Department at Highland hospital. During my post-baccalaureate and before medical school, I spent a significant amount of time traveling and volunteering in Latin America and South East Asia. While applying to medical school, I worked at UCSF's Osher Center for Integrative Medicine on a mindfulness-based HIV study and in the Family Medicine Department working as a health coach. At Creighton University School of Medicine, I have been actively involved as a manager of the homeless health clinic, global health and family medicine interest groups. I am passionate about women's health, global health, public health, social justice, and palliative care. Outside of medicine I love traveling and meeting people along the way, reading, hiking/camping, cooking and dinner parties, yoga, and coffee shop hoping. I am a city girl at heart who loves the outdoors and I looking forward to meeting everyone and experiencing all that Chestnut Hill and Philadelphia have to offer!

You can email Dr. Postone at

Ashanda Powell, M.D., Co-Chief


I grew up in North Philadelphia and attended Masterman Middle and High School. I continued my education at Johns Hopkins University as a Biology major. At Hopkins, I was able to build my interest in medicine and in particular, primary care. After graduating from Hopkins, I took a year off from school and was employed as a Substance Abuse Research Assistant both in Baltimore and Philadelphia. I matriculated into Temple University School of Medicine in 2009 and from that point my interest in primary care grew. I applied for Family Medicine positions along the east coast, but ultimately chose Chestnut Hill for its camaraderie amongst residents and the supportive nature of the teaching staff and environment. In my free time I like to swim, run, walk trails and relax with friends and family.

You can email Dr. Powell at

Ashley Ruby, M.D.


I've spent my entire life in Pennsylvania starting with growing up in York. I went to Lehigh University in Bethlehem for my undergraduate education in Behavioral Neuroscience, and then moved to Philly to attend Drexel University College of Medicine. I fell in love with Family Medicine during my rotation as a 3rd year med student. I love having the opportunity to learn so many unique facets of medicine and to treat such a wide variety of patients. I believe Chestnut Hill Family Practice will be the perfect place for me to get a great education in a community atmosphere where everyone is close and supportive of one another. In my free time, I enjoy cooking and eating, spending time with friends, cuddling with my dog, playing with my mice, and catching up on my TV shows.

You can email Dr. Ruby at

Paul Skomra, M.D.


I was born in Buffalo, New York and was raised in Jupiter Florida. I was fortunate enough to spend my childhood in the sun under the guidance and support of my wonderful family and friends. As a youth, I was very involved with my community and church, which led me to participate in several mission trips to aid the under-served. These experiences helped me gain perspective as well as a strong desire to help communities, families, and individuals. I completed my undergraduate at the University of Florida where I studied Public Health, which led me to attend Ross University School of Medicine. While at Ross, I was able to pursue my passion for healthcare, experience diversity, and learn invaluable lessons of acceptance, humility, and self-discipline. The experiences during medical rotations, mainly throughout New York City, solidified my decision to pursue a career in Family Medicine. I find that this field considers all other fields while extensively impacting a broad patient base. Chestnut Hill was my top choice due to its welcoming staff, diverse patient population, and its excellent reputation. In my free time I enjoy traveling, live music, exercising, and spending time with friends and family.

You can email Dr. Skomra at

Second Year

Maria Dormans, M.D.


After spending most of my life in Pennsylvania, I knew I wanted to return to the Keystone State for my residency training. I was raised in the small town of Mountain Top and decided to stay in Northeastern Pennsylvania for my undergraduate education. I attended The University of Scranton where I obtained a bachelor’s degree in biology. My educational journey continued at St. George’s University in Grenada where my interest in medicine, different cultures and traveling were combined. St. George’s provided me the unique opportunity to follow in my father’s footsteps while carving my own path in medicine. My adventure continued during clinical rotations in New York City where I got to experience why family medicine is appealing to me: the diversity of not only the patient population but also the range of diseases that make this field a continual challenge. I am excited to join the Chestnut Hill community and establish relationships with patients of all ages and cultural backgrounds while exercising and expanding my medical knowledge.

You can email Dr. Dormans at

John Sebastian Jaeger, M.D


Originally hailing from California, I went to college in New England and taught middle schoolers English in a small Japanese town before moving to Ohio for medical school, Virginia for an internship and then Indiana to work before joining the Chestnut Hill family. I am happy to say my peripatetic path in life has led me to Philadelphia and the opportunity to serve the Chestnut Hill community. I am drawn to Family Medicine for the wide ranging scope of practice and the primary care practitioner’s unique role within the community and in the changing landscape of medicine in this country as a whole. Professionally, I’m drawn to aspects of utilization management, cost control, evidence based best practices and the way forward for a health care system that encompasses integrative, holistic approach to health throughout a person’s lifetime. Outside of the hospital, other interests include backpacking and traveling. I hope to be able to practice overseas someday as well. I look forward to all the challenges and opportunities to learn in residency!

You can email Dr. Jaeger at

Marcus Ng, M.D.


Born in the heart of NYC, I was among the first in my family to be born in the USA. While my parents worked hard to ensure that I had a comfortable life, I was raised in Queens by my grandparents who instilled in me their ideals and dreams of success in America. They taught me how to be a good person; how to empathize with others, learn from my surroundings, and be a person others could depend on. I carried their teachings close to heart as I earned my BA in Biology at the Macaulay Honors College at CUNY Hunter, leading me to attend the University at Buffalo School of Medicine. There, while working with patients from all walks of life, I grew to appreciate how the primary care field resonated with my own values. I loved being able to help anyone who walked through my door and becoming intimately familiar with all aspects of my patients healthcare. This is what brings me to Chestnut Hill Family Practice Residency, where I hope to continue learning to become a solid clinician with their diverse patient population and excellent, supportive staff. So long as I may be forgiven for my allegiances to certain NY sports franchises, I look forward to my time here working with the people of Philadelphia.
If I am not at the hospital, you may find me traversing nearby hiking trails, enjoying the culinary delights of the city, exploring the local music scene, or catching up on my knitting.

You can email Dr. Ng at

Janet Sim, M.D.


Hello! I am Janet Sim, born and raised in Seattle, Washington. I come from a Korean-immigrant family and lived in Seattle until moving to the New England area to attend Dartmouth College for my undergraduate years. Then I moved to Cincinnati, Ohio to attend the Master’s in Physiology program and later matriculated into the University of Cincinnati College of Medicine. During my first summer in medical school, I took care of my grandmother which sparked an interest in geriatrics and palliative care, but I am keeping my options open and look forward to the opportunities available at Chestnut Hill Family Practice Residency. During my free time I enjoy cooking (mostly Korean food), fishing, reading comic books, and trying to live life to the fullest.

You can email Dr. Sim at

Natalia Uribe, M.D.


I am originally from Medellin, Colombia and was raised in Miami, FL. From an early age I dreamed of being a doctor, driven by a desire to help people. I attended public school in Miami and received a B.S. in Biology from the University of Miami, where through volunteering, I fostered my interest in education and understanding of social context. I then attended Drexel University College of Medicine, where I discovered the great value that Family Physicians have for communities and families, especially within today's healthcare system. While at Drexel, I have worked in varied communities and learned about the importance of culture and the social determinants of health and wellbeing. I am interested in health education, public health, and issues of access to health care and seek to become a well-rounded physician that is able to care for any community, family, and individual.

You can email Dr. Uribe at

Danielle Williams, M.D.


I was born and raised in the great city of Baltimore, Maryland. After high school I attended Hampton University in Hampton, Virginia. There I recognized my passion for community service and knew I would one day incorporate it into my career. I came to Philadelphia for a post baccalaureate program and then medical school at Drexel University College of Medicine. During that time I fell in love in and with Philadelphia and knew I did not want to leave. I chose Family Medicine because I believe preventive health is the key to staying well and living life to its fullest potential. Chestnut Hill was an obvious choice for me because of its reputation for great training, the warmth I felt from the staff, and its location in a part of Philadelphia to which I feel personally connected. In my free time I enjoy spending time with my family, jogging along Kelly drive, cooking, and traveling.
You can email Dr. Williams at

First Year

Corey Cramer, M.D.


I was born on the Southern New Jersey shore, but my father's military career eventually brought me Tampa, Florida for the better part of my childhood. During high school I was given the opportunity to participate in two humanitarian efforts in Liberia and Sierra Leone, which inspired me to pursue a career in healthcare. After high school my family and I moved back home to New Jersey and I began my undergraduate education studying Biology at Stockton University. I spent several months volunteering at Mukinge Mission Hospital in Zambia after graduating, at which point I decided to pursue my degree in medicine. I went on to attend Drexel University College of Medicine, and over the course of my education was increasingly drawn to family medicine; the diversity in patient populations, the variety of medical conditions and most importantly the continuity of patient care that encourages a focus on overall well-being were all attributes that first drew me to medicine. I'm thrilled to continue my training with the Chestnut Hill Family Practice program, especially since that means I get to stay in the great city of Philadelphia and continue to root for my Phillies and Flyers.

You can email Dr. Cramer at

Dennis Cullen, M.D.


I grew up in Washington DC, and moved to Bethlehem for college where I received a bachelor's degree in History from Lehigh University. After college, I worked in finance and then executive search. That was 2009 during that economic downturn, and my job was to find people that other companies could hire, but no companies were hiring. So I spent much of that time eating Chinese food on the conference room table while watching Maury. As fun as that was, it wasn't a good long term career plan, so I applied for a job as a scribe in the ER in Fairfax, VA. After about eighteen months I applied to St. George's University, was accepted, and completed my medical education in Brooklyn by way of Grenada. I'm very much looking forward to continuing my training at Chestnut Hill.

You can email Dr. Cullen at

David Johnson, M.D.


As a lifetime resident of Pennsylvania, I am thrilled to have the opportunity to serve and give back to my community. Since the age of 10, I have been focused on becoming a Family Medicine Doctor working with a breadth of populations at home and abroad. As an undergrad at Grove City College, I majored in Molecular Biology. My training in medicine at The Commonwealth Medical College was tailored to developing excellent community-based primary care. I've had the opportunity to serve many times in Africa and in Latin America and hope to continue doing so throughout my career. I know that my continued education at Chestnut Hill, with its reputable track record of producing excellence, will develop my skills as a physician to be versatile, knowledgeable, and compassionate. In my free time, I would consider my interests wide and varied, from running, biking, dancing, and just about any sport, to hydroponic gardening, reading, cooking, and socializing.

You can email Dr. Johnson at

Nina Keyvan, M.D.


I was born and raised in New York. I majored in biology at Johns Hopkins University, and I attended University of Illinois College of Medicine. While I enjoyed living in the Midwest, I was excited to return to the East Coast when I began my intern year at Chestnut Hill Hospital. As I am interested in working in the community and focusing on preventative care, family medicine seemed like the perfect fit. My first impression of Chestnut Hill Hospital was a warm and welcoming place with a dedicated group of residents and faculty members. I was truly impressed by the cohesive and supportive team dynamic. It was important for me to have a strong and well-rounded training environment while serving a diverse patient population. I am very excited to embark on this new journey with a fun and hard-working group of co-residents.

You can email Dr. Kevyan at

Ammar Shahid, M.D


I was born and raised in New Jersey before coming to Philadelphia for undergraduate studies and medical school. I completed my undergraduate degree in Biology at Drexel University and subsequently attended medical school at Drexel University College of Medicine. My interest in family medicine stems from my experience in medical school, when I was actively involved in helping organize a free clinic for the impoverished people of Philadelphia. I look forward to practicing family medicine because of the wide variety of patients one encounters, the continuity of care in practice one experiences, and the emphasis on preventative care in the field. In my free time, I enjoy playing basketball, biking, reading, traveling, and spending time with friends and family.

You can email Dr. Shahid at

Jaquelyn Rohui Yeh, M.D.


Hi! I’m Jaquelyn. I grew up in Los Angeles, California, where I also attended California State University, Los Angeles. I was part of the Early Entrance Program, where I skipped high school and attended college full-time starting at the age of 13. I then moved to Chicago for medical school at Chicago Medical School. I was drawn to family medicine because I love the versatility of this field and the relationships I can build with my patients that last a lifetime. I have interests in women’s health, adolescent health, and sports medicine. I chose Chestnut Hill Hospital Family Practice Residency because I loved their strong curriculum, supportive faculty, and close-knit residents. I am very excited to start my residency in Philadelphia. In my free time, I enjoy exploring the beautiful city, baking (I make amazing chocolate chip cookies), watching movies, reading, writing, dancing, and traveling.

You can email Dr. Yeh at