Most travel insurance plans do not provide coverage for pre-existing conditions, due to the short-term nature of the plans. However, some plans provide coverage for acute onset of a pre-existing condition, which is defined as a sudden and unexpected outbreak or recurrence of a pre-existing condition which occurs spontaneously and without advance warning in the form of physician recommendations or symptoms, is of short duration, is rapidly progressive, and requires immediate medical attention. The insured may be covered for pre-existing conditions only if the individual's attending physician determines that his or her pre-existing condition is acute. The acute onset must occur after the effective date of the policy. Treatment must be obtained within 24 hours of the sudden and unexpected outbreak or recurrence. A pre-existing condition that is a chronic or congenital condition or that gradually becomes worse over time will not be considered acute onset. To learn more, visit our page about Acute Onset of Pre-Existing Conditions.