Pressures for cost containment followed the 1965 passage of Medicare and Medicaid, the public insurance programs initiated under President Lyndon Johnson's administration that offered coverage to elderly people, people with disabilities, and low income children and families who had been left out of private insurance plans. With more Americans covered by either public or private insurance, greater use of health services became a pattern that invited a new paradigm of "managed care" to monitor costs, utilization, and quality. Insurance companies adopted "selective contracting," or signing up only a fraction of health care providers in given communities.Utilization review panels looked over service usage patterns in physicians' offices and hospitals to ensure that only the most "medically necessary" services were delivered.