http://www.ncsl.org/research/health/con-certificate-of-need-state-laws.aspx

Certificate of Need (C.O.N.) programs are aimed at restraining health care facility costs and allowing coordinated planning of new services and construction.  Laws authorizing such programs are one mechanism by which state governments seek to reduce overall health and medical costs.  Many “CON” laws initially were put into effect across the nation as part of the federal “Health Planning Resources Development Act” of 1974.  Despite numerous changes in the past 30 years, about 36 states retain some type of CON program, law or agency as of 2016.