Prescription Drug COST (Control Overspending to Save Taxpayers) Containment Act of 2005 - Directs the Secretary of Health and Human Services to: (1) provide for a one-year delay in the enrollment of individuals in the Voluntary Prescription Drug Benefit Program under Medicare part D; (2) continue to provide for the Medicare prescription drug discount card and transitional assistance program under Medicare part D during 2006 under the same terms and conditions that apply during 2005; and (3) continue to provide for coverage of prescription drugs under the Medicaid program during 2006 under the same terms and conditions that apply during 2005.