Objectives.The specialty referral process is one of the chief targets of managed care constraints on ambulatory medical decision-making. This study examines the influence of gatekeeping arrangements and capitated primary care physician (PCP) payment on the specialty referral process in primary care settings.Research Design.Primary care practice-based study of referred and nonreferred office visits.Subjects.The study comprised 14,709 visits made by privately insured, nonelderly patients who were seen by 139 primary care physicians in 80 practices located in 31 states.Measures.Visits were grouped by health plan type: gatekeeping with capitated PCP payment; gatekeeping with fee-for-service PCP payment; no gatekeeping. Dependent measures included the proportion of visits referred, characteristics of referrals, and physician coordination activities.Results.The percentages of office visits resulting in a referral were similar between the two gatekeeping groups and higher than the no gatekeeping group. Patients in plans with capitated PCP payment were more likely to be referred for discretionary indications than those in nongatekeeping plans (15.5% v 9.9%,P<0.05). The frequency of referring physician coordination activities did not vary by health plan type. The proportion of patients in gatekeeping health plans within a practice was directly related to employing staff as referral coordinators, allowing nurses to refer without physician consultation, and permitting patients to request referrals by leaving recorded telephone messages.Conclusion.The specialty referral process for privately insured nonelderly patients enrolled in managed health plans is generally similar, regardless of the presence of gatekeeping arrangements and capitated PCP payment. An increase in the number of discretionary referrals among patients in plans with capitated PCP payment provides support for exploring strategies that encourage PCPs to manage in their entirety conditions that straddle the boundaries between primary and specialty care. In response to increasing numbers of patients enrolled in managed health plans with gatekeeping arrangements, physicians appear to modify the structure of their practices to facilitate access to and coordination of referrals.