Objective: The seven-vaccine series protects infants from several preventable diseases, yet disparities in its use remain in the United States. Methods: We assessed the seven-vaccine immunization rate and its predictors in infants 19-35 months using the National Immunization Survey from 2009 to 2018. Results: The seven-vaccine series rate was 72.8%, well short of the healthy people 2020 target of 90%. African American infants, infants born to mothers with less than high school education, and infants in families with an income below poverty were less likely to get the complete series. Conclusion: Disparities still exist in protecting infants from preventable diseases in the United States.