Nursing home markets are likely to deviate from a competitive structure because of limitations on entry imposed by Certificate of Need (CON) regulations and the potential for product differentiation along such attributes as location, religious affiliation and quality. This paper investigates the structure of nursing home markets in New York State by calculating price mark ups and residual private pay demand elasticities. It shows that the residual demand elasticity is bound by estimates based on price mark ups above marginal costs and above Medicaid rates. This approach allows estimation of demand elasticities in all markets, whether or not CON regulations constrain bed supply. Mean price elasticities (in absolute value) calculated for nursing homes in New York State in 1991 ranged from 3.46 to 3.85.