Most international medical plans exclude pre-existing conditions. Why?

International medical insurance is available to all nationalities traveling outside of their home country worldwide. Coverage is guaranteed without underwriting, which means all applicants who have paid premiums are automatically covered regardless of their medical history. No medical questions are asked and pre-existing conditions are generally always excluded. Travel insurance plans that are limited to US and Canadian residents often have a waiver for pre-existing condition exclusions in the event certain conditions are met.