may add or drop health plans, increase or decrease the types of services covered, increase (but rarely cut) the level of employee cost sharing, change provider networks, or make other major and minor changes in the health benefits offered to employees. Some individuals lose some or all coverage when they voluntarily or involuntarily change jobs or move from welfare to working status. Others suffer ''job lock" or "welfare lock" rather than voluntarily give up medical coverage. Sometimes financial protection is continuous following a job change, but the continuity of medical care is still disrupted because the new job's health plan requires a change of health care practitioner. Such discontinuity of care for those with serious health problems is likely to become an increasingly important issue as more employers and health plans attempt to restrict individuals to defined networks of health care practitioners and providers. Through their national health plans or regulatory standards for sickness funds and similar organizations and their general commitment to universal coverage for basic health services, other countries limit the likelihood that changes in job status or employers' policies will interrupt care or coverage.
Whether the measure is health spending as a percentage of the gross national product or spending per capita, the United States is noted for spending considerably more on health care than other nations. Employers' capacities and incentives to manage health benefit programs effectively are quite uneven and will remain so. Managing health benefits is a secondary issue in most employers' visions of their future and in their priorities, and some seem to feel that pressing hard on health care costs may, at some point, actually undermine employee morale and other values. At their best, employers' skills in health benefit management can be quite sophisticated, but this sophistication is generally limited to the largest employers. At their worst, employers rely for cost containment on risk segmentation, discrimination, and excessive intervention in patient-clinician decisionmaking. Direct evidence that employers' cost containment efforts make a difference, especially for overall health care costs, is very limited . On the other hand, the track record for public cost containment strategies is not dramatically more positive.
Several of the features singled out above—diversity, discontinuity, risk segmentation—contribute to another distinctive feature of the U.S. health care system: the immense complexity of its public and private methods for providing and managing health benefits. A great array of differing coverage