Dr. Joel Marc Rubio is Guam’s first endocrinologist and physician in Internal Medicine and Endocrinology, Diabetes, and Metabolism, and a Fellow of the American College of Endocrinology. He has completed advanced postgraduate training in areas including thyroid ultrasound and biopsy, obesity medicine, nuclear medicine in endocrinology, and procedural medicine, allowing him to provide comprehensive, specialized care for patients with complex endocrine and metabolic conditions.

He earned his Doctor of Medicine from the University of the East–Ramon Magsaysay Memorial Medical Center in Quezon City, Philippines, graduating in the top tier of his class. He completed his rotating internship at the University of the Philippines–Philippine General Hospital Medical Center, followed by a medical externship at Guam Memorial Hospital. Dr. Rubio then completed his Internal Medicine residency at Saint Barnabas Hospital, part of the Cornell University Training Program in Bronx, New York, and went on to complete a subspecialty fellowship in Endocrinology at the State University of New York at Stony Brook Medical Center.

Throughout his career, Dr. Rubio has held numerous leadership roles in both clinical practice and academic medicine. He is the Founding Partner and Head of Clinical Services at Health Partners, LLC in Tamuning, Guam, and has served as Active Staff in Endocrinology and Internal Medicine at Guam Memorial Hospital. His professional background also includes roles as a department head, consultant, clinical assistant professor, and visiting consultant in both the United States and the Philippines.

In addition to his clinical work, Dr. Rubio has contributed to medical research, publications, and physician education, and has held leadership positions within professional organizations, including serving as President of the Guam Medical Society. As a long-standing provider in Guam’s medical community, Dr. Rubio now practices at GRMC, where his expertise continues to strengthen the hospital’s ability to deliver integrated, high-quality care for patients with complex medical needs.

• Doctor of Medicine
  June 1981 – April 1985
  University of the East-Ramon Magsaysay Memorial Medical Center
  Quezon City, PH

• Philippine College of Physicians
• American College of Endocrinology
• Philippines Professional Regulatory Commission Licensing Examination for Physicians
• American Association of Clinical Endocrinologists
• American Medical Association
• Guam Diabetes Association
• Guam Medical Society
• Philippine Diabetes Association

• Founding Partner, Head of Clinical Services, Health Partners, LLC, Private Practice, Endocrinology and Internal Medicine
• Active Staff, Endocrinology and Internal Medicine, Guam Memorial Hospital
• Private Practice, Endocrinology and Internal Medicine, Hafa Adai Specialist Group
• Head, Department of Internal Medicine, Pacificare Asia-Pacific
• Chief, Endocrinology, Clinical Assistant Professor in Endocrinology, Department of Medicine, De la Salle University Medical Center
• Private Practice, Endocrinology, Mercado General Hospital
• Private Practice, Endocrinology, St. Francis Cabrini Hospital
• Private Practice, Endocrinology, De la Salle University Medical Center
• Consultant, Endocrinology, Fort Med Medical Care Center
• Consultant, Endocrinology, Pacificare
• Visiting Consultant, Endocrinology and Internal Medicine, Manila Doctors’ Hospital
• Visiting Consultant, Endocrinology and Internal Medicine, Calamba Medical Center
• Attending Physician, Private Practice, Endocrinology and Internal Medicine, Primary Care of Southbury
• Attending Physician, Endocrinology Division, Department of Internal Medicine, Danbury Hospital
• Attending Physician, Yale University School of Medicine
• Staff Physician, Medical Service, Veterans Administration Medical Center
• Associate Medical Staff, Emergency Medicine, Saint Barnabas Hospital
• Associate Medical Staff, Internal Medicine and Intensive Care, Union Hospital
• President, Guam Medical Society
• Member, House of Delegates, American Medical Association
• Board Member, Upsilon Sigma Phi North America
• President, Guam Medical Society
• Board Member, University of the Philippines Alumni Association of Guam
• Chairperson, Medical Credentialing Committee, Guam Memorial Hospital
• Member, Medical Executive Committee, Guam Memorial Hospital
• Member, Physicians Advisory Committee to the Board of Trustees, Guam Memorial Hospital