Travel insurance is optional, but highly recommended by the U.S. Department of State. The decision around buying it will depend on your own personal risk tolerance, how much you’ve paid in non-refundable costs for the trip, and whether your regular health insurance will provide coverage for expenses you incur while you’re on the trip.
If you’re traveling within the U.S., your regular health plan will provide emergency coverage even if you have to be treated at an out-of-network emergency room. (This is due to the Affordable Care Act and the No Surprises Act.) But if you’re leaving the country, you may find that your current plan will not provide any travel health insurance coverage.
You may not feel that you need coverage for issues like the costs of trip cancellation or lost luggage. (You may, for instance, feel comfortable taking a loss on those expenses if necessary, or feel confident that your credit card provides adequate protection.) But the idea of being without health coverage in a foreign country may make some people at least consider travel medical insurance. And depending on where you’re traveling, you may need to show proof of medical insurance in order to obtain a visa.