The changeover to the metric system in the United States is motivated by our manufacturing industry. The basic reason for the changeover is economic necessity, which dictates also that changes to metric be made only where they are advantageous. In the transition timetable, our manufacturing industry and our educational institutions are already well started. Now, then, is the time also for the development of national metric engineering standards to supersede or supplement our customary engineering standards. Government procurement will keep in step with industry changeover. Consumer products will be changed some years hence, the specific time being dependent on the enactment of national metric legislation, but early programs should be initiated to keep our public informed as to why the changeover is taking place and how it is progressing. The principal role of Government in the changeover is to keep SI, the modernized metric system, as clean as possible. When metric legislation is enacted, a National Metric Conversion Board will have the responsibility for coordinating the changeover. Meanwhile the American National Metric Council has undertaken this role.