Ten ways HMOs have changed during the 1990s.

The same forces that encouraged the expansion of managed care also brought about change in health maintenance organizations (HMOs). Using data from annual surveys of the Association of American Health Plans and other sources, this paper examines ten major changes in the HMO industry during the 1990s, including the growth of for-profit plans and the relative decline of nonprofits; the shift from vertically integrated group/staff models to virtually integrated individual practice associations/network models; industry consolidation through mergers and acquisitions; increased patient cost sharing; and the shift to capitation payment of primary care physicians. Current research is unable to show whether these changes have led to improved quality of care or patient satisfaction.