This final rule with comment period revises the Medicare hospital outpatient prospective payment system to implement applicable statutory requirements and changes arising from our continuing experience with this system, and to implement certain related provisions of the Medicare Prescription Drug, Improvement, and Modernization Act (MMA) of 2003 and the Deficit Reduction Act (DRA) of 2005. In this final rule with comment period, we describe changes to the amounts and factors used to determine the payment rates for Medicare hospital outpatient services paid under the prospective payment system. These changes are applicable to services furnished on or after January 1, 2007. In addition, this final rule with comment period implements future CY 2009 required reporting on quality measures for hospital outpatient services paid under the prospective payment system. This final rule with comment period revises the current list of procedures that are covered when furnished in a Medicare-approved ambulatory surgical center (ASC), which are applicable to services furnished on or after January 1, 2007. This final rule with comment period revises the emergency medical screening requirements for critical access hospitals (CAHs). This final rule with comment period supports implementation of a restructuring of the contracting entities responsibilities and functions that support the adjudication of Medicare fee-for-service (FFS) claims. This restructuring is directed by section 1874A of the Act, as added by section 911 of the MMA. The prior separate Medicare intermediary and Medicare carrier contracting authorities under Title XVIII of the Act have been replaced with the Medicare Administrative Contractor (MAC) authority. This final rule continues to implement the requirements of the DRA that require that we expand the "starter set" of 10 quality measures that we used in FY 2005 and FY 2006 for the hospital inpatient prospective payment system (IPPS) Reporting Hospital Quality Data for the Annual Payment Update (RHQDAPU) program. We began to adopt expanded measures effective for payments beginning in FY 2007. In this rule, we are finalizing additional quality measures for the expanded set of measures for FY 2008 payment purposes. These measures include the HCAHPS survey, as well as Surgical Care Improvement Project (SCIP, formerly Surgical Infection Prevention (SIP)), and Mortality quality measures.