of managed care enrollment in Medicaid over the past decade, a majority of immunizations are currently administered in the private sector.
In 1998, according to the National Immunization Survey (NIS), 54.6 percent of U.S. children received immunizations from private providers, 16.9 percent from public providers, 7.9 percent from mixed providers (public and private), and 20.5 percent from other providers3 (CDC, 1999e). In 1998, an estimated 55 percent of all U.S. children were enrolled in employer-sponsored health plans that covered pediatric immunizations (KPMG Peat Marwick, 1998; Bureau of the Census, 1999). Information on the provision of adult immunization benefits by private plans is lacking.
The rise of managed care has caused public health services, such as immunizations, to be increasingly privatized and funded through capitated arrangements, which makes it difficult to document immunization services. For example, the number of Americans that receive health care services from health maintenance organizations (HMOs) increased from 6 million in 1976 to 67.5 million in 1996 (NVAC, 1999a). The proportion of Medicaid beneficiaries enrolled in a managed care arrangement increased from less than 15 percent in 1993 to 54 percent in 1998 (Health Care Financing Administration [HCFA], 1999b). In addition, 2 million low-income children previously ineligible for Medicaid have been enrolled in the State Children’s Health Insurance Program (SCHIP) over the past 2 years, and the majority of these children receive their vaccines from private providers (HCFA, 2000a). Consequently, children who were likely to be immunized in the public sector 10 years ago may no longer be eligible for its services.
Over the past decade, both general and immunization-specific pediatric best practices have included immunizations within the child’s medical home (AAP, 1992). Administration of immunizations in a timely manner by the child’s primary care practitioner is viewed as a quality measure in its own right and as an indicator of access to a broader array of preventive and routine primary care services. There will always be conditions and population groups that require some kind of special effort, such as children attending school for the first time, adolescents who need immunizations recently added to the schedule (e.g., hepatitis B), or migrant children served by mobile clinics. However, the preferred immunization setting is the child’s regular source of primary care.
Yet the enrollment of Medicaid and SCHIP beneficiaries in private managed care organizations has led to uncertainties and tensions regarding the appropriate site for delivering publicly financed vaccines. Some clients still rely on public clinics for immunizations, either because the public clinic is more convenient (in terms of hours of service or geographic location) or because of the relatively low cost of vaccines thus