Certification of Need (CON) laws aim to establish the optimal mixture of health facilities and services in a community. In most areas, the initial step has been to limit construction of facilities for acute hospital beds, thus exerting pressure on the profession to use ambulatory facilities more widely than before. The rationale is a demonstrated limitation in resources available, even in an affluent society, for health care. Most of the 20 states that have enacted CON laws require that all projects involving more than $100,000 capital expenditure be approved by a designated state agency. The Social Security Amendments of 1972 support states that enact CON laws by excluding nonconforming institutions from reimbursement for capital expenditures through federally funded programs. It is predicted that many more states will seek the economies in health care that the laws strive to promote.