The science of drug testing in chronic pain has advanced rapidly over the past few years. Yet there is still confusion around optimal test choices, frequencies, and what test results actually provide. Today's definitive drug testing technology can help to identify more than the simple "presence or absence" of drugs, such as possible drug-drug interactions, variations in individual metabolism that could impact medication efficacy or side effects, potential genetic variations in metabolism, and more. This case based session will focus on patient centered, guideline driven drug testing, and medical necessity documentation to support definitive drug testing. Attendees will participate and help to complete case studies with practical clinical resources that can be immediately incorporated into their practice setting.