A few insurance companies will allow you purchase travel insurance for a “one way” trip, however conditions and exclusions may apply.  CSA will allow for one way travel from the US or Canada providing the trip does not exceed 31 days. Travel Insured International will allow purchase for a one way trip, but you will not receive a waiver for the pre-existing conditions exclusion even if purchased within 14 days of first deposit.  Always refer to the policy certificate prior to purchase for the full details of the plan.