Telehealth Response for E-prescribing Addiction Therapy Services Act or the TREATS Act This bill modifies requirements relating to coverage of certain telehealth services under Medicare. Specifically, the bill permanently allows telehealth services for substance-use disorders to be provided via audio-only technology, if a physician or practitioner has already conducted an in-person or video telehealth evaluation. Schedule III or IV controlled substances may also be prescribed online if a practitioner has conducted a telehealth evaluation with video.