My Child Is Behind on Vaccines — What Do I Do?

Why does catch-up vaccination work?

Vaccine schedules are designed for ideal timing, but the immune system is flexible. If doses are missed, the catch-up schedule simply continues the series at the right intervals. A child who missed the second dose of a three-dose series does not restart from zero — they receive the remaining dose or doses and pick up where the schedule left off.

The Advisory Committee on Immunization Practices (ACIP) publishes official catch-up schedules as part of the annual childhood immunization schedule 1Ref 1Issa AN, Wodi AP, Moser CA, Cineas S (2025).Advisory Committee on Immunization Practices Recommended Immunization Schedule for Children and Adolescents Aged 18 Years or Younger — United States, 2025.ACIP publishes official catch-up schedules for children; catch-up vaccination continues from where the series left off and is age-stratified. These schedules are tested, evidence-based, and safe. Multiple vaccines can be given at the same visit without overwhelming a child's immune system — this is standard practice endorsed by the ACIP's general best-practice guidelines 2Ref 2Centers for Disease Control and Prevention (2024).Chapter 2: General Best Practice Guidance for Immunization (Epidemiology and Prevention of Vaccine-Preventable Diseases, The Pink Book).Multiple vaccines can be given simultaneously without overwhelming the immune system; re-vaccinating is safe; live vaccines require special consideration in immunocompromised children.

What happens at a catch-up visit?

At the appointment, the provider reviews your child's immunization record — or requests it from the state registry if you do not have it. They identify which vaccines are overdue, how many doses remain in each series, and map out a follow-up schedule so you know exactly what comes next and when.

Bring any vaccination records you have: original cards, school records, or patient portal printouts. Also bring your child's full name, date of birth, name and address of previous pediatricians, and school enrollment paperwork showing which vaccines are required.

What if you do not have vaccination records?

Two approaches exist when records are lost or unavailable:

• Check the state immunization registry. Most states maintain a registry of all vaccines given within that state.
• Re-vaccinate or check titers. Re-vaccinating from scratch is safe — you will not cause harm by repeating a dose 2Ref 2Centers for Disease Control and Prevention (2024).Chapter 2: General Best Practice Guidance for Immunization (Epidemiology and Prevention of Vaccine-Preventable Diseases, The Pink Book).Multiple vaccines can be given simultaneously without overwhelming the immune system; re-vaccinating is safe; live vaccines require special consideration in immunocompromised children. Alternatively, a blood test (titer) can check for existing antibody levels before giving doses, potentially reducing the number of injections needed.

The pediatrician will help you decide which approach makes sense based on your child's age and history.

Why do kids fall behind on shots?

Children miss scheduled vaccines for many reasons: a gap in care, insurance changes, moving, illness during a scheduled visit, or a family decision to delay. Whatever the reason, the path forward is the same — contact a provider and schedule the catch-up. The goal is to get the child protected as efficiently and comfortably as possible.

What about school immunization requirements?

Most states have school immunization requirements with specific deadlines. A medical exemption or conditional enrollment can sometimes allow a child to attend while completing a catch-up series under a documented plan. Contact the school nurse and your pediatrician together — they can coordinate the documentation.

If your child needs vaccines before starting a new school year or transferring, bring this to the appointment so the provider can prioritize the required vaccines.

Special situations that affect the catch-up plan

Child's age. The catch-up schedule differs by age group. Adolescents follow a slightly different schedule than younger children, and some vaccines (such as certain meningococcal doses) are first recommended at age 11–12. The provider tailors the plan to your child's exact age 1Ref 1Issa AN, Wodi AP, Moser CA, Cineas S (2025).Advisory Committee on Immunization Practices Recommended Immunization Schedule for Children and Adolescents Aged 18 Years or Younger — United States, 2025.ACIP publishes official catch-up schedules for children; catch-up vaccination continues from where the series left off and is age-stratified.

International adoption or immigration. Children adopted internationally or recently immigrated may have vaccination records in a foreign format or language. Some foreign vaccines are considered equivalent; others may not be. A pediatrician experienced with international adoption or refugee health can review foreign records and decide what to accept or repeat.

Underlying health conditions. Children with immune system conditions, certain cancers, or who take immunosuppressive medications may need a modified vaccine plan. Some live vaccines are avoided in this group 2Ref 2Centers for Disease Control and Prevention (2024).Chapter 2: General Best Practice Guidance for Immunization (Epidemiology and Prevention of Vaccine-Preventable Diseases, The Pink Book).Multiple vaccines can be given simultaneously without overwhelming the immune system; re-vaccinating is safe; live vaccines require special consideration in immunocompromised children.

Cost. Children who are Medicaid-eligible, uninsured, underinsured, or Alaska Native/American Indian may receive vaccines at no cost through the Vaccines for Children (VFC) program 3Ref 3Centers for Disease Control and Prevention (2025).About the Vaccines for Children (VFC) Program.VFC program provides no-cost vaccines to Medicaid-eligible, uninsured, underinsured, and American Indian/Alaska Native children ages 18 and younger through participating providers. Ask the clinic if they participate.