Health care reengineering is a powerful methodology that helps organizations reorder priorities, provide more cost-effective care, and increase value to customers. It should be driven by what the customer wants and what the market needs. Systemwide reengineering integrates three levels of activity: managing community and health plan partnerships; consolidating overlapping delivery system functions among participating providers and vendors; and redesigning administrative functions, clinical services, and caregiving programs to improve health status. Reengineering is not a panacea; it is a critical core competency and requisite skill for health care organizations if they are to succeed under managed care in the future.