Medicare Mental Health Modernization Act of 2005 - Amends title XVIII (Medicare) of the Social Security Act (SSA) to provide for: (1) elimination of the lifetime limit on inpatient mental health services; (2) parity in treatment for outpatient mental health services; (3) coverage of intensive residential services under Medicare part A (Hospital Insurance) and of intensive outpatient services under Medicare part B (Supplementary Medical Insurance); (4) exclusion of clinical social worker services from coverage under the Medicare skilled nursing facility prospective payment system; and (5) coverage of marriage and family therapist services and mental health counselor services under Medicare.
Directs the Secretary of Health and Human Services to study and report to Congress on whether the criteria for coverage of any therapy service or any oupatient mental health care service under Medicare unduly restricts the access to such a service of any Medicare beneficiary with Alzheimer's disease or a related mental illness because the coverage criteria requires the Medicare beneficiary to display continuing clinicial improvement to continue to receive the service.