The 2nd character defines the particular body system or general physiological system or anatomical region involved.
Substance abuse treatment codes have a first character value of “H”. 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. Examples include detoxification services and individual counseling. The fourth character is a type qualifier that further specifies the procedure type. The individual counseling procedure further specified in the fourth character includes the values Cognitive Behavioral, 12-step, and Interpersonal. The fifth, sixth and seventh characters are not specified and always have the value None.