DSM IV Criteria Bipolar II Disorder

A) Presence (or history) of one or more Major Depressive Episodes

B) Presence (or history) or at least one Hypomanic Episode

C) There has never been a Manic Episode or a Mixed Episode

D) The mood symptoms in Criteria A and B not better accounted for by Schizoaffective Disorder and is not superimposed on Schizophrenia, Schizophreniform Disorder, Delusional Disorder, or Psychotic Disorder Not Otherwise Specified.

E) The symptoms cause clinically significant distress or impairment in social, occupational, or other important areas of functioning.

(Note: there are additional ways of coding for billing and diagnostic features such as severity and additional symptoms, but the fundamental diagnostic criteria for Bipolar remain the same.)