The Centers for Disease Control and Prevention (CDC) announced in July 2005 that childhood immunization coverage for children aged 19–35 months was at an all time high. Childhood immunizations for the baseline series of vaccines (4:3:1:3:3) were 80.9 percent, exceeding, for the first time, the Healthy People 2010 goal of 80 percent coverage (CDC 2005
). Despite this progress, there are still disparities in immunization status by race/ethnicity, income and insurance status, as well as by state of residence and urban or rural location (Department of Health and Human Services 2000
; Luman et al. 2005
Initiatives to further increase immunization coverage for children have focused primarily on missed opportunities in private physician practices and policies to reduce financial barriers. Efforts have been made to promote increases in tracking and record keeping by private physicians, the use of centralized immunization registries, and other strategies such as automated reminder and recall (CDC 2004
The federal Vaccines for Children Program (VFC) was designed to reduce financial barriers by providing vaccine doses free of charge to eligible children through public and private providers (Santoli et al. 1999
). Children who are American Indian/Alaska Native, uninsured, or enrolled in Medicaid are eligible to receive federally purchased vaccines at participating private clinics. Children with private health insurance coverage that does not cover immunizations—or those with coverage with high copayments and deductibles (i.e., the underinsured)—are also eligible to receive VFC vaccines but only in federally qualified health centers or rural health clinics (Santoli et al. 1999
). In 2006, the VFC program was expected to provide free vaccine dosage to approximately 37 million eligible children (0–18 years of age) in over 44,000 provider sites, of which 73 percent were private providers (CDC 2007
The passage of the State Children's Health Insurance Program (SCHIP) in 1997 has also contributed to decreasing financial barriers to immunization by providing subsidized health insurance coverage to low-income children. The program has contributed to a significant increase in the number of children with public health insurance coverage through increased enrollment in both SCHIP and Medicaid, and a reduction of two million uninsured children (Robert Wood Johnson Foundation 2005
While there has been an increase in public program participation by children through Medicaid and SCHIP, most children (65 percent in 2006) are still covered by private health insurance (DeNavas-Walt, Proctor, and Smith 2007
). There are three specific concerns with private health insurance coverage related to immunization coverage: gaps in private health insurance coverage over time, increasing copayments and deductibles leading to increased financial barriers for prevention services, and lack of coverage for immunization benefits.
Many children experience gaps in their coverage for significant periods of time. It has been estimated that approximately 9 percent of children under age 18 experience gaps in health insurance coverage. These gaps have been shown to contribute to delays in seeking needed medical care and addressing unmet medical care needs (Olson, Tang, and Newacheck 2005
; Cohen and Martinez 2006
). It has been demonstrated that even short gaps in health insurance coverage have negative impacts on immunization status for children in the first 2 years of life (Wood 2003
There has also been a significant change in the nature of private employer-based health insurance. There has been a significant drop in employer-based coverage, with the percentage of firms offering health benefits falling from 69 percent in 2000 to 60 percent in 2005 (Gabel et al. 2005
). Recent evidence documents the source of the decline to include a drop in employer-sponsored coverage (48 percent), a drop in the number of employees taking up insurance (27 percent), an increase in ineligible employees (14 percent), and a decrease in dependent coverage (11 percent) (Clemans-Cope and Garrett 2006
). While SCHIP and Medicaid have been filling the gap for low-income children, there is little evidence about the children who are falling between the cracks—children whose parents no longer have employer-based coverage but with incomes too high for public program eligibility. These are the children most likely to experience gaps in private health insurance coverage.
Another concern is the reduction in private health insurance benefits, including coverage for immunizations. “A recent article by the American Academy of Pediatrics found that 20 percent of employers were offering catastrophic health insurance plans (high deductible health plans), up from only 5 percent in 2003, and only 30 percent of these plans covered preventive care before the deductible was met” (Lee et al. 2007
, p. 642). Another study estimated that approximately one out of five U.S. children with private health insurance had no immunization coverage and another 6 percent had private insurance with significantly high copayments and deductibles (Wood et al. 2004
In this study, we examine the impact of health insurance coverage on the immunization coverage rates for very young children (age 19–35 months). We specifically look at the impact of full-year and part-year health insurance coverage on immunization status for a nationally representative sample of young children. Understanding the nature of health insurance coverage may help in identifying new strategies to increase immunization coverage.