Vaccinations against polio, whooping cough, Haemophilus influenzae type b (Hib), and hepatitis B virus (HepB) are all given to infants in the first 6 months of life in the United States according to the CDC’s recommended immunization schedule. It is unclear when further monovalent immunizations should be given to infants after they have received diphtheria, tetanus, and acellular pertussis (DTaP) based pentavalent combination vaccine. Births registered in the US MarketScan commercial claims and encounters database between July 1, 2010, and June 30, 2018, were included in this retrospective cohort analysis. Vaccine administration rates were analyzed with descriptive statistics. The parameters associated with the delivery of DTaP-IPV/Hib and HepB were investigated using multivariate logistic regression. Most (91.5%-98.3%) of the Hib doses claimed for babies who received DTaP-HepB-IPV (n=129,885) were given on the same day as the DTaP-HepB-IPV dosages. For the total sample size of 214,172 infants who were given DTaP-IPV/Hib, 95.3% had claims for more than equal to 2 doses of HepB. Coverage was good, but only 59.2% of children received their second HepB dose on the same day as their first DTaP-IPV/Hib dose, and only 44.6% of children received their third HepB dose on the same day as their third DTaP-IPV/Hib dose. Region of residence, provider type, health plan type, and the administration of pneumococcal conjugate vaccination and rotavirus vaccine were all found to have significant effects on the coadministration of the second and third doses of HepB with DTaP-IPV/Hib. Almost every baby got their recommended course of monovalent vaccines. However, many infants in this study did not finish the HepB series until 9 months, which is later than the recommended age for the other vaccines (DTaP, IPV, and Hib).