If you’re traveling abroad this summer, the last thing you probably want to think about is what you'll do if you get sick or injured. But experts say 15 percent of travelers encounter some kind of medical problem on their journey, and depending on your destination, your U.S. health insurance may not be much use.

The good news is that if you have to look beyond your own health plan, there are ways to cover medical emergencies that can be surprisingly inexpensive. Here’s what you need to think about.

Check your existing health plan. Coverage varies by health insurer and plan, so you must contact your carrier to get the details of your specific policy, says Cathryn Donaldson, a spokeswoman for the America's Health Insurance Plans trade association. In most cases, Medicare does not cover you outside the U.S., while some Medicare Advantage and Medigap plans do offer worldwide emergency care.

"Most domestic health plans provide limited coverage overseas and won't cover prescriptions abroad," says Margaret Wilson, M.D., chief medical officer of UnitedHealthcare Global, which is part of the largest health insurer in the U.S.

Aetna, for example, generally covers its policyholders when they embark on foreign travel, but the care is reimbursed as "out-of-network," which is typically subject to higher out-of-pocket costs

The Centers for Disease Control and Prevention recommends that you grill your insurer about: Exclusions for injuries related to terrorist attacks, acts of war, natural disasters, adventure activities like scuba diving and mountain climbing, and exacerbations of pre-existing conditions; whether pre-authorization is needed for treatment, hospital admission, or other services; and the deductibles, copays, limits, and other policies for out-of-network services.

Consider international travel health insurance. If your examination finds gaps in your existing healthcare policy, the CDC and major carriers like Aetna, Kaiser Permanente, and UnitedHealthcare say you should consider filling the holes with a supplemental international travel health insurance plan. These plans provide secondary coverage that picks up the costs where your primary health insurance stops; some provide primary coverage.

Beware exclusions for pre-existing conditions. Travel health insurance policies typically don't cover pre-existing conditions. But you can buy a waiver of that exclusion, and you should consider doing so if you've had a change in your health, treatment, or medicines in the 180 days before you buy the coverage, says Lynne Peters, director of product at InsureMyTrip.com, a broker of travel insurance, international travel health insurance, and medical evacuation insurance.

Shop wisely for travel health insurance. You and your travel itinerary are unique, so you want to have multiple health plans and carriers to choose from, to tailor coverage to your exact needs. Shop at a broker that gives you options. Two with especially large selections are InsureMyTrip (800-487-4722), which sells more than 250 policies from 28 insurance companies, and SquareMouth (800-240-0369), which offers 112 policies from 22 insurers. Use these websites' toll-free phone numbers to get precise guidance from a human agent.

Policies tend to cost less the younger the traveler and the less comprehensive the plan. A $1 million medical insurance plan with zero deductible could cost a 35-year-old less than $15 a week, says Peters. The same medical coverage for a 65-year-old–but with a pre-existing medical condition waiver, medical evacuation, and $5,000 trip cancellation/interruption coverage–could cost $220 to more than $600 a week, according to Peters.

Be prepared to pay up front for overseas medical care. Even if you're covered by your regular U.S. health policy and supplemental travel health insurance, you should be ready to pay up front for medical care you receive abroad. That's because most foreign healthcare providers require payment in cash or by credit card when you receive treatment, and only some U.S. insurers have direct billing and payment relationships with healthcare providers all over the world, says Wilson.

Some international travel health plans also require that you pay up front and get reimbursed later, while others pay providers a certain amount on the spot to get you treated and admitted. The GeoBlue international travel health plans, however, have a global network of 7,100 physicians and 2,000 facilities in 190 countries, which the insurer pays directly, if you get treated there.

Of course, you can't choose where you'll fall ill or be injured. So you must have ready money. "Even with international coverage, consider carrying an extra credit card with a large limit to use for unanticipated medical expenses," says Wilson. To ensure proper and prompt reimbursement by your insurers, Wilson advises that you get clear and complete copies of all bills, medical records, and discharge notes after you receive treatment.

Add medical evacuation protection. Not every travel destination in the world has doctors and hospitals that are up to U.S. standards, and many locations have none. If you're traveling in a developing country or a remote destination that's way off the grid, the CDC advises that you consider purchasing yet another type of protection called medical evacuation insurance. It covers the cost of medical transportation that can fly you hundreds or thousands of miles to a major city with quality medical care.

International air ambulances aren't cheap. They can cost $20,000 to $250,000, depending on departure point and destination as well as medical complexity, says Dr. William Siegart, chief medical officer of On Call International, one of the major services providing medical evacuations.

Although the need for medevac is relatively uncommon, On Call International handled more than 17,000 medical cases in 2016, including nearly 1,700 medical transports. Its 24-hour, 365-days-a-year service connects to a network of 4,000 medical centers and numerous air ambulance and commercial medical transport providers worldwide.  

Medical evacuation insurance also covers the high cost of repatriating a recovering traveler to the United States on a commercial flight with a rescue nurse and necessary medical equipment, which can can cost $10,000 to $50,000.

In the U.S., medical-emergency helicopters are often “out of network” and not fully covered by insurance, so you definitely want to ask your health insurer if medevac is covered overseas.

Kaiser Permanente, for example, covers local emergency medical transportation to the nearest hospital or other facility, if it determines that's necessary. But it doesn't generally cover or arrange other transportation, unless it deems it necessary to manage the member’s care.

If repatriation is approved by Kaiser, it will pay for that service directly. But a Kaiser spokeswoman says members should consider supplemental medevac insurance "to lessen potential financial liability for non‐covered travel‐related expenses."