Compassionate Access, Research Expansion, and Respect States Act of 2015 or the CARERS Act of 2015 Amends the Controlled Substances Act (CSA) to provide that control and enforcement provisions of such Act relating to marijuana shall not apply to any person acting in compliance with state law relating to the production, possession, distribution, dispensation, administration, laboratory testing, or delivery of medical marijuana. Transfers marijuana from schedule I to schedule II of the CSA. Excludes "cannabidiol" from the definition of "marijuana" and defines it separately as the substance cannabidiol, as derived from marijuana or the synthetic formulation, that contains not greater than 0.3% delta-9-tetrahydrocannabinol on a dry weight basis. Deems marijuana that is grown or processed for purposes of making cannabidiol, in accordance with state law, to meet such concentration limitation unless the Attorney General determines that the state law is not reasonably calculated to comply with such definition. Prohibits a federal banking regulator from: (1) terminating or limiting the deposit insurance of a depository institution solely because it provides or has provided financial services to a marijuana-related legitimate business; or (2) prohibiting, penalizing, or otherwise discouraging a depository institution from providing financial services to a marijuana-related legitimate business. Prohibits a federal banking regulator from recommending, motivating, providing incentives, or encouraging a depository institution not to offer financial services to an individual, or to downgrade or cancel financial services offered to an individual, solely because: (1) the individual is a manufacturer of marijuana, (2) the individual&nbsp;is or later becomes an owner or operator of a marijuana-related legitimate business, or (3) the depository institution was not aware that the individual is the owner or operator of a marijuana-related legitimate business.  Prohibits a federal banking regulator from taking any adverse or corrective supervisory action on a loan to an owner or operator of: (1) a marijuana-related legitimate business soley because the owner or operator is such a business, or (2) real estate or equipment that is leased to a marijuana-related legitimate business solely because it is leased to such a business Provides depository institutions that provide financial services to a marijuana-related legitimate business protection under federal law from federal criminal prosecution or investigation, criminal penalties, and forfeiture of legal interest in collateral solely for providing financial services to such a business.  Directs: (1) the Department of Health and Human Services to terminate the Public Health Service interdisciplinary review process described in the guidance entitled "Guidance on Procedures for the Provision of marijuana for Medical Research" (issued on May 21, 1999), and (2) the Drug Enforcement Administration to issue at least three licenses under CSA registration requirements to manufacture marijuana and marijuana-derivatives for research approved by the Food and Drug Administration.  Directs the Department of Veterans Affairs (VA) to authorize VA health care providers to provide veterans with recommendations and opinions regarding participation in state marijuana programs.
Output: Compassionate Access, Research Expansion, and Respect States Act of 2015