Globally, one of the biggest reasons why children aren’t immunized on time is that their caregivers don’t always remember the children’s vaccination dates. As a result, children are immunized late or incompletely, which puts them at a greater risk of contracting and dying of a vaccine-preventable disease. Inspired by our firsthand experiences with Peruvian mothers and nurses, we designed simple bracelets to help mothers from resource-poor areas more easily remember their children’s vaccination dates. By using only numbers and symbols, the bracelets convey the number and type of all routine childhood vaccinations needed and the dates of all vaccination appointments. The award-winning bracelets are low cost ($0.10 each), safe for the babies who wear them, and can be adapted to any region or community because they are not language-specific.