Final answer:
The US coding system used for chemical dependency services inpatient outpatient service for substance use (addiction) is the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5).
Step-by-step explanation:
The US coding system used for chemical dependency services inpatient outpatient service for substance use (addiction) is the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5). DSM-5 is used by clinicians to diagnose individuals suffering from various psychological disorders, including drug use disorders. The criteria for specific substance use disorders are described in DSM-5.