How do Medicare coverage policies, under national coverage determinations (NCDs) and local medical review policies (LMRPs), affect claims, access and cost? The researchers examined eight procedures that fall into three policy categories: new technology, extension of existing technology, and utilization management. The study included an examination of changes in the use of the eight procedures over the period 1999-2001 to answer the following research questions: 1) Do LMPRs or NCDs affect local practice patterns in Medicare? 2) Are there different effects for distinct categories of policies? 3) If an NCD applies to all providers and beneficiaries, can we expect consistency in utilization patterns in Medicare following the implementation of a national policy? 4) If LMRPs are consistent across local contracts, should we see consistency in utilization post-policy implementation? 5) To the extent that LMRPs applicable to the same procedures vary from region to region, should we expect to see variations in practice that reflect these policy differences? and 6) If variations in utilization persist in light of similar policies, how can those variations in practice patterns be explained? The objective of this study was to provide insights to policy makers on the effectiveness of coverage policies, the appropriate balance between national and local decisions, and implications for efforts to enact contractor reform.