Dr. Theodore Li graduated from Columbia University in 1973 and from Cornell University Medical College in 1977. He completed his residency in Internal Medicine at The New York Hospital-Cornell Medical Center in New York City in 1980 and spent part of that time working with the Cornell-International Rescue Committee Medical Team in a Cambodian refugee camp in Eastern Thailand. From 1981-83, he was a Henry J. Kaiser Fellow in General Internal Medicine at Harvard Medical School and the Brigham and Women's Hospital. Following one year on the Harvard faculty, Dr. Li moved to Georgetown University Hospital where he spent five years in the Division of General Internal Medicine. In 1989, Dr. Li went into private practice with three other members of the Georgetown faculty; in 1999 he joined Foxhall Internists.

In addition to practicing medicine, Dr. Li regularly participates in the instruction of medical students and residents. He has also been active in the assessment of practicing physicians and was a director of the American Board of Internal Medicine from 1996-2000. He continues to work on question-writing committees for the ABIM.