First and foremost, watch out for duplicate coverage. Always check with your health insurer, as well as your homeowners, life and auto policies to see if you already have coverage for some of the travel risks you face.
For example, if you're a member of AAA, you actually have benefits that are quite similar to some of the travel policies out there. These are the kinds of things you should look into.
The next step is to assess your trip. What are the risks? Say you're going out of the country for an extended period. Emergency medical coverage can be really valuable if your regular health insurance doesn't already cover you while abroad.
While premiums can vary based on age and trip length, a typical plan will cost between $50 to $100 for a short international trip. This relatively small investment can save you from potentially catastrophic bills in case anything goes wrong.
So, is travel insurance necessary? Usually not, but be sure to assess your risks. Check existing coverage before you buy and don't pay for plans that cover small, manageable losses. Safe travels.