F23.3 exists in the World Health Organization's base ICD-10 classification, but was never adopted into ICD-10-CM (the United States clinical modification used for medical billing). It cannot be used on a US claim. Reference information from the official WHO classification is shown below.
Code
F23.3
Title
Other acute predominantly delusional psychotic disorders
Definition
Acute psychotic disorders in which comparatively stable delusions or hallucinations are the main clinical features, but do not justify a diagnosis of schizophrenia (F20.-). If the delusions persist the diagnosis should be changed to persistent delusional disorder (F22.-).
Includes
Source: WHO ICD-10 (International Statistical Classification of Diseases and Related Health Problems, 10th Revision)