John J. Messmer, MD

4.8 out of 5 from 352 Patient Satisfaction Ratings. Learn more about the survey.
John J. Messmer, MD
Employed by Penn State Health
Family Medicine, Geriatric Medicine

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About Me

John Messmer, MD, grew up in Conshohocken, PA near Philadelphia and is a graduate of Penn State College of Medicine. Dr. Messmer started his residency in family medicine at St. Margaret Memorial in Pittsburgh, PA and finished at the Naval Hospital in Charleston, SC. After eight years in the Navy Medical Corps, he entered private, solo practice in Palmyra, PA. He became certified in geriatrics in 1993.

Dr. Messmer's involvement in medical student education lead to his practice becoming the Penn State Hershey Medical Group, Palmyra in 1995 where he has served as Medical Director for most of that time. Dr. Messmer is also oversees the Family and Community Medicine inpatient service.

Dr. Messmer is Treasurer of the Lebanon County Medical Society and a Fellow of the American Academy of Family Physicians. He has served as President of the Penn State College of Medicine Alumni Society and as an elected member of the Penn State Alumni Association. He is a member of the Doctors Kienle Center for Humanistic Medicine.

Dr. Messmer emphasizes preventive care of the entire family with particular emphasis on seniors and end of life care.


Accepted Insurances

We accept a variety of health insurance plans and will submit claims on your behalf. Certain coverage restrictions may apply based on your individual benefit package.

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Professional Education


Medical School, Penn State College of Medicine - 1977


Residency, Family Medicine Naval Hospital - Charleston, SC - 1984


Internship, Family Medicine St Margaret Memorial Hospital-UPMC - 1978


  • Listed in Best Doctors in America for Family Medicine and Geriatrics