For most travelers coming from the U.S. or Europe, there are no legally required vaccinations to enter Costa Rica, but several are strongly recommended for your health. The CDC and WHO generally suggest being up to date on routine "jabs" like Measles-Mumps-Rubella (MMR) and Tetanus. For travel-specific protection, Hepatitis A and Typhoid are recommended due to potential exposure through food or water, even in developed tourist areas. A specific requirement exists for Yellow Fever: if you are arriving from a high-risk country (such as certain nations in South America or Sub-Saharan Africa), you must show an International Certificate of Vaccination. While Costa Rica is largely safe, 2026 advisories also highlight the importance of mosquito prevention due to risks of Dengue and Zika, so while there isn't a widely required jab for these yet, carrying high-quality repellent is just as essential as your medical preparations.