Guidance, Understanding, and Information for Dual Eligibles (GUIDE) Act - Directs the Secretary of Health and Human Services to establish a three-year demonstration program under which the Secretary awards grants and contracts to appropriate, qualified community programs and clinics for individuals with intellectual or developmental disabilities, or certain programs under the Public Health Services Act, to employ qualified social workers and case managers to provide one-on-one counseling about benefits under part D (Voluntary Prescription Drug Benefit Program) of title XVIII (Medicare) of the Social Security Act (SSA) to a full-benefit dual eligible individual (eligible for benefits under both Medicare and SSA title XIX [Medicaid]) who has one or more mental disabilities.