There are several situations where you may not need travel insurance. If you are traveling domestically, purchased a cheap ticket, and have health insurance that will cover you, you probably do not need travel insurance.
Additionally, if you used frequent flier miles for your flight, points for your hotel, and are traveling domestically, you may not need travel insurance.
If you’re traveling internationally and you’ve paid for a lot of non-refundable travel expenses up front, you would want to purchase travel insurance.
This is because your health insurance may not cover you abroad, and you’d want to be protected. You also have significant funds at risk should you become ill and not be able to travel.