The 2nd character defines the particular body system or general physiological system or anatomical region involved.
Mental Health procedure codes have a first character value of “G”. The second character is used to identify the body system elsewhere in ICD-10-PCS. Because body system does not apply in this section, the second character always has the value None. The third character specifies the root type, such as crisis intervention or counseling. The fourth character is a type qualifier (e.g., to indicate that counseling was educational or vocational). The fifth, sixth and seventh characters are not specified and always have the value None.