On February 24, 2010, a 13-valent pneumococcal polysaccharide-protein conjugate vaccine (PCV13 [Prevnar 13, Wyeth Pharmaceuticals Inc., marketed by Pfizer Inc.]) was licensed by the Food and Drug Administration (FDA) for prevention of invasive pneumococcal disease (IPD) caused among infants and young children by the 13 pneumococcal serotypes covered by the vaccine and for prevention of otitis media caused by serotypes also covered by the 7-valent pneumococcal conjugate vaccine formulation (PCV7 [Prevnar, Wyeth]). PCV13 contains the seven serotypes included in PCV7 (serotypes 4, 6B, 9V, 14, 18C, 19F, and 23F) and six additional serotypes (serotypes 1, 3, 5, 6A, 7F, and 19A). PCV13 is approved for use among children aged 6 weeks-71 months and supersedes PCV7, which was licensed by FDA in 2000. This report summarizes recommendations approved by the Advisory Committee on Immunization Practices (ACIP) on February 24, 2010, for the use of PCV13 to prevent pneumococcal disease in infants and young children aged <6 years. Recommendations include 1) routine vaccination of all children aged 2-59 months, 2) vaccination of children aged 60-71 months with underlying medical conditions, and 3) vaccination of children who received ≥1 dose of PCV7 previously (CDC. Licensure of a 13-valent pneumococcal conjugate vaccine [PCV13] and recommendations for use among children-Advisory Committee on Immunization Practices [ACIP], 2010. MMWR 2010;59:258-61). Recommendations also are provided for targeted use of the 23-valent pneumococcal polysaccharide vaccine (PPSV23, formerly PPV23) in children aged 2-18 years with underlying medical conditions that increase their risk for contracting pneumococcal disease or experiencing complications of pneumococcal disease if infected. The ACIP recommendation for routine vaccination with PCV13 and the immunization schedules for children aged ≤59 months who have not received any previous PCV7 or PCV13 doses are the same as those published previously for PCV7 (CDC. Preventing pneumococcal disease among infants and young children: recommendations of the Advisory Committee on Immunization Practices [ACIP]. MMWR 2000;49[No. RR-9]; CDC. Updated recommendation from the Advisory Committee on Immunization Practices [ACIP] for use of 7-valent pneumococcal conjugate vaccine [PCV7] in children aged 24-59 months who are not completely vaccinated. MMWR 2008;57:343-4), with PCV13 replacing PCV7 for all doses. For routine immunization of infants, PCV13 is recommended as a 4-dose series at ages 2, 4, 6, and 12-15 months. Infants and children who have received ≥1 dose of PCV7 should complete the immunization series with PCV13. A single supplemental dose of PCV13 is recommended for all children aged 14-59 months who have received 4 doses of PCV7 or another age-appropriate, complete PCV7 schedule. For children who have underlying medical conditions, a supplemental PCV13 dose is recommended through age 71 months. Children aged 2-18 years with underlying medical conditions also should receive PPSV23 after completing all recommended doses of PCV13.