Included in this report are some individual State's approaches to implementing medical marijuana laws and a comparison of these approaches with the results of any State audits or reviews; the number, age, gender, and medical conditions of patients that have had doctors recommend marijuana for medical use in each State; the number of doctors known to have recommended marijuana in each State and the guidance for making these recommendations; and the perceptions of Federal and State law enforcement officials and whether data are available to show how the enforcement of State marijuana laws has been affected by the introduction of these States' medical marijuana laws. Appendices includes objectives, scope and methodology, including State selection and data and law enforcement opinions; U.S. Supreme Court's decision in United States v. Oakland Cannabis Buyers' Cooperative; medical marijuana registries in Oregon, Alaska, Hawaii, and select California counties; descriptions of allowable conditions under State medical marijuana laws; comments from the Department of Justice; GAO contacts and staff acknowledgments. There are 11 tables including, for example, registry requirements and verification procedures in Oregon, Alaska, and Hawaii as of July 2002; number of marijuana recommendations made by Oregon physicians as of February 2002; safety and public use restrictions in Oregon, Alaska, Hawaii, and California; and doctor guidance provided by selected State medical organizations. Figures provide information on examples of Oregon's, San Francisco's, Alaska's, and Hawaii's medical marijuana registry or certification cards.