 In 1973, a law was enacted which forced all employers to participate in the medical insurance of their workers, by means of a direct payment to their workers' insurance plans.The duty of participation was eventually changed and diminished in 1991.Until the enactment of the National Health Insurance Law in 1995, the Israeli healthcare system was based on voluntary membership of Israeli citizens in one of four independently operating Sick Funds, known as Kupot Holim, which were responsible for providing medical care to their members.