This article examines the association between characteristics of local heal
th cave market areas in 1982 and the penetration of new organizational form
s in those markets in 1995. The Novtheast and South exhibit less organizati
onal form development than the West. Local markets with higher population s
ize and greater density of specialty physicians in 1982 are associated with
greater proportions of the markets being covered by a wide variety of orga
nizational forms in 1995.