Phi Alpha Gamma (ΦΑΓ) was a professional fraternity for homeopathic medicine founded at the New York Homeopathic Medical College in 1894. Once the largest medical fraternity in the United States, It merged with Phi Chi in 1948.

Phi Chi (ΦΧ) is one of the oldest and largest international medical fraternities of its kind in the world. Phi Chi evolved from the merging of two professional medical fraternities bearing the same name. Phi Chi Society was founded on March 31, 1889, at the University of Vermont, Burlington, Vt. Phi Chi Medical Fraternity was founded on October 26, 1894, at the Louisville Medical College, Louisville, Ky. These two organizations did not know that they shared a similar name when they were founded. On March 5, 1905, in Burlington, Vt., Phi Chi Society and Phi Chi Medical Fraternity, Inc., were consolidated taking the name Phi Chi Medical Fraternity, Inc.