Sick and disabled Americans who rely on Medicare may gain new access to care with the proposed settlement of a lawsuit that challenged the government's practice of denying some coverage to patients whose condition was not improving. Medicare is required by law to cover healthcare services that are "reasonable and necessary for the diagnosis or treatment of illness or injury." But the 47-year-old program does not cover what is called custodial care, including much nursing home care. Under the terms of the settlement Medicare would not deny skilled nursing care and various forms of therapy for beneficiaries, regardless of their prognosis.