The WHO program on essential medicines advises governments about how to determine which medicines are needed to meet the health care needs of the majority of the population and how to make them available to everyone. A Model List of these medicines proposed in 1977 included 186 drugs; the current list exceeds 300. The principle of making essential medicines available to everyone is accepted by 156 countries. Implementation is variable. Problems currently being considered for solution include whether drugs effective for rare diseases are ever essential and getting pediatric dosage forms of essential drugs manufactured and registered for sale. With all societies dealing with the rising cost of medical care and having to make choices, the concept of essential medicines is a relevant to all now as it was to countries with limited resources when the WHO program started in 1975.