This non-profit organization has provided clinical services to both in- and out-patients, and engages in research, education, and social outreach.

Following the success of Karl's book, The Human Mind, Menninger presented a paper to the American Psychiatric Association in 1937.

At the outset of World War II, Menninger left the family foundation for an appointment as the director of the Psychiatry Consultants Division in the office of the Surgeon General of the United States Army.

He chaired the committee which produced document Medical 203, a major revision of existing US classification of mental disorders.

Following the war, this document strongly influenced the first mental disorders section of the International Statistical Classification of Diseases published in 1949.