How do the pre-existing conditions exclusion and waiver work?

Answer:

A pre-existing condition is any injury or illness that is in existence 60 to 180 days (depending on product purchased) prior to and including the date your insurance coverage goes into effect. For most policies, if the condition is controlled (that is, if you don't need to change your medication or treatment during the 60-180 day period), it's not considered a pre-existing condition. You can waive this exclusion under certain policies if you purchase within 10 - 21 days, depending on the policy you purchase, of paying your initial deposit for the trip. There are a few policies which will waive the pre-existing exclusion if policy is purchased prior to making the final trip payment.