Principal Diagnosis
When more than one diagnosis for an individual is given in an inpatient setting, the prin-
cipal diagnosis is the condition established after study to be chiefly responsible for occa-
sioning the admission of the individual. When more than one diagnosis is given for an
individual in an outpatient setting, the reason  for visit is the condition that is chiefly re-
sponsible for the ambulatory care medical servic es received during the visit. In most cases,
the principal diagnosis or the reason for visit is also the main focus of attention or treat-
ment. It is often difficult (and somewhat ar bitrary) to determine which diagnosis is the