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John Joseph Messmer, M.D.

Office Location

Penn State Hershey Medical Group Palmyra
941 Park Drive
Palmyra, PA 17078
Tel: 800-243-1455 / 717-838-6305 Fax: 717-838-5332


Family Medicine Geriatric Medicine

Patient Services Provided

Preventive Medicine Dermatology Family Medicine Geriatric Medicine Nursing Home Care Office Procedures - joint injections/management of dermatologic (skin) conditions

Biographical Information

John Messmer, M.D. 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 & 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.

Professional Education

Residency, Family Medicine, Naval Hospital - Charleston, SC (1984) Internship, Family Medicine, Saint Margaret Memorial Hospital (1978) M.D., Penn State Hershey College of Medicine (1977)

Academic Interests

Dr. Messmer teaches Profession of Medicine, Foundations of Patient Centered Care (clinical interviewing and physical diagnosis), Medical Humanities, Family Medicine clinical clerks and the Medical Home Longitudinal Curriculum.


Naeye RL, Messmer J, Specht T, Merritt TA
Sudden Infant Death Syndrome Temperament Before Death
Messmer J
Vision Loss in Paulman: Taylor's Differential Diagnosis Manual 3rd Ed.
Messmer J
PCMH: What About the Patient?
Messmer J
Chronic Disease Registries: Implementation and Spread
Messmer JJ
LASIK: a primer for family physicians. Am Fam Physician
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Honors and Awards

Listed in Best Doctors in America for Family Medicine and Geriatrics