1. Short title This Act may be cited as the Medicare and Opioid Safe Treatment Act or the MOST Act . 2. Medicare coverage of certain services furnished by opioid treatment programs (a) Coverage Section 1861(s)(2) of the Social Security Act ( 42 U.S.C. 1395x(s)(2) ) is amended— (1) in subparagraph (FF), by striking at the end and ; (2) in subparagraph (GG), by inserting at the end ; and ; and (3) by adding at the end the following new subparagraph: (HH) opioid use disorder treatment services (as defined in subsection (jjj)). . (b) Opioid use disorder treatment services and opioid treatment program defined Section 1861 of the Social Security Act is amended by adding at the end the following new subsection: (jjj) Opioid use disorder treatment services; opioid treatment program (1) Opioid use disorder treatment services The term opioid use disorder treatment services means items and services that are furnished by an opioid treatment program for the treatment of opioid abuse disorder, including— (A) opioid agonist treatment medications (including oral versions) that are approved by the Food and Drug Administration under section 505 of the Federal Food, Drug and Cosmetic Act for use in the treatment of opioid use disorder; (B) dispensing and administration of such medications, if applicable; (C) substance abuse counseling by a professional to the extent authorized under State law to furnish such services; (D) behavioral individual and group therapy with physicians or psychologists (or other mental health professionals to the extent authorized under State law); (E) toxicology testing; and (F) other items and services that the Secretary determines are appropriate. (2) Opioid treatment program The term opioid treatment program means an opioid treatment program (as defined in section 8.2 of title 42 of the Code of Federal Regulations, or any successor regulation) that— (A) is enrolled under section 1866(j)