Ask your parents, former physicians and school administrators. Parents and doctors are responsible for retaining personal vaccination records, according to the CDC. Many schools hold records on file, but some may limit the length of time -- 24 months, for example -- they keep records of former students on file.
Contact your city or state health department. Most cities and states have provisions for vaccine providers -- physicians, for example -- to report vaccine records to health departments within 30 days. The city of Baltimore, for instance, maintains an immunization registry program that allows physicians and parents to fax records to the health department to help parents and guardians keep child vaccinations up to date.
Go online and visit the CDC website. Click on the "Programs and Tools" link in the main menu on the home page. Select the "IIS (Immunization Information Systems/Registries)" tab. Choose from the "Contacts" and "States and Territories" links to find your state IIS information. Return to the home page, if necessary, and type in "Find Your Child's Immunization Record Through Your State's IIS" in the search box. Click "Enter" to find a CDC page listing state and local IIS contact information. Contact an IIS representative and inquire about your records. Present your personal ID and complete all necessary release forms as requested. The purpose of the IIS is to computerize and track vaccination records of children in all 50 states.