Unfortunately, because your first payment was several months ago and you have paid for your entire trip already, you are outside of the parameters for all travel insurance policies that offer a pre-existing exclusion waiver. Most policies require you purchase your insurance within 10 -21 days of the initial payment for your trip. A few policies by CSA Travel Protection and HTH Worldwide allow you to receive cover in the event you have made some deposits for your trip, but still have your final trip payment left to make. It may be helpful to understand how insurance carriers define a “pre-existing” condition. They will generally exclude any condition for which you exhibited symptoms or sought medical treatment for during the last 2 to 6 months depending on the policy. Conditions controlled solely through medication with no change in the medication during the “look back” period, are not considered pre-existing by most insurance policies.