Your Original Medicare insurance covers a wide variety of health services, from flu shots to inpatient hospital stays and hospice care. But it doesn’t cover everything, and it doesn’t cover all of your out-of-pocket costs.

Many services covered by Original Medicare require co-payments, co-insurance or deductibles. But you can purchase supplemental insurance to cover these “gaps” in Medicare. Such insurance is called, appropriately, Medigap. Some Medigap policies also cover certain benefits that Original Medicare doesn’t, such as emergency care in a foreign country.
You have to pay for Medigap yourself, and it’s sold through private insurance companies. You can buy it only if you have Original Medicare, not Medicare Advantage.
Every Medigap policy has to follow federal and state laws designed to protect you. Medigap insurance companies in most states can only sell you a “standardized” Medigap policy identified by letters A through N. Each standardized policy must offer the same basic benefits, no matter which company sells it.
So beware when you’re shopping for a Medigap policy: Cost is usually the only difference between Medigap policies with the same letter sold by different companies. And there can be big differences in how much various insurers charge for exactly the same coverage.
Here are some of the costs a Medigap policy may cover:
» Medicare Part A (hospital) co-insurance and hospital costs for up to 365 days after Medicare benefits run out
» Medicare Part B (doctor’s charges) co-insurance or co-pays
» Blood (first three pints)
» Part A hospice care co-insurance or co-pays
» Skilled nursing facility co-insurance
» Part A and Part B deductibles
Medigap policies generally don’t cover long-term care (such as care in a nursing home), vision or dental care, hearing aids, eyeglasses and private-duty nursing.
The best time to buy a Medigap policy is during your Medigap open enrollment period. This period lasts for six months and begins on the first day of the month in which you’re both 65 or older and enrolled in Medicare Part B.
Why is this important? Because during open enrollment, an insurance company can’t refuse to sell you any Medigap policy it offers because of any health problems you may have. Nor can you be charged more based on your health status.
In some cases, however, an insurer can refuse to cover your out-of-pocket costs for pre-existing health conditions for up to six months. After six months, the Medigap policy will cover the pre-existing condition.
And remember, for Medicare-covered services, Original Medicare will still cover the condition even if the Medigap policy won’t cover your out-of-pocket costs. But you’re responsible for the co-insurance or co-payment.
A few other points to keep in mind:
» You must have Medicare Part A and Part B to buy a Medigap policy.
» Plans E, H, I, and J are no longer for sale, but you can keep these plans if you already have one.
» A Medigap policy only covers one person. If you and your spouse both want Medigap coverage, you must each buy a separate policy.
» Any standardized Medigap policy is guaranteed renewable, even if you have health problems. This means the insurance company can’t cancel your policy as long as you pay the premium.
Although some Medigap policies sold in the past cover prescription drugs, Medigap policies sold after Jan. 1, 2006, aren’t allowed to include prescription drug coverage. (If you want such coverage, you can join a Medicare Part D prescription drug plan, offered by private companies approved by Medicare.)
— David Sayen is the regional administrator for Arizona, California, Hawaii, Nevada and the Pacific Trust Territories for the U.S. Centers for Medicare & Medicaid Services. For answers to Medicare questions 24/7, call 800.MEDICARE.