Anyone 65 years of age and over who has signed on for Medicare is likely going to realize that Medicare only covers a finite group of health care costs, leaving gaps in their medical insurance coverage. To help pay some of the health care costs that standard Medicare does'nt cover, such as co-payments, co-insurance and deductibles, there is Medicare supplemental insurance plan - also known as Medigap - which may cover what Medicare doesn't cover.

"When you choose a Medigap plan, it is important to find the best policy for you," said Alan Weinstock, insurance broker at "Medicare Supplement Plans". "Seniors should talk to someone who knows [about it] and can help them compare rates, plans and benefits for Medicare supplement insurance before they buy."

For older Americans who are ready to choose a Medicare supplemental insurance policy, here are five tips to help them learn further about Medigap insurance.

Medigap Insurance and the Policies Companies Sell:
There are Medigap plans ranging from A through L; however, while the insurance companies can sell only standardized Medicare supplement insurance policies, they don't have to offer every Medigap plan. There is a caveat, though: Insurance companies must offer Medigap Plan A if they offer any other Medigap policy. State laws may also affect which plans are offered by companies.

Important Information about Medigap Policies:
In order to buy a Medigap policy, there are some important points you need to know:

• You need to have Medicare Part A and Part B.
• There are monthly premium rates you have to pay for Medicare supplemental insurance.
• Your policy cannot be cancelled, even for health reasons, as long as you pay your premium.
• Each plan only covers one person. That means you and your spouse will have to buy separate policies.

Choosing the Best Time to Buy Medicare Supplement Insurance:
The best time to buy Medigap insurance is during your Medigap open enrollment period, which is the six-month period that begins on the first day of the month in which you turn 65 and enroll in Medicare Part B. During this period, insurance companies cannot use medical underwriting, so they cannot refuse to sell you a Medigap policy, charge you more because of health problems or make you wait for coverage to start, except in some cases for pre-existing conditions.

After the open enrollment period, Medigap insurance companies are generally allowed to use medical underwriting. Therefore, there is no guarantee they will sell you a policy.

Insurance Company Pricing of Medicare Supplement Insurance:
Insurance companies decide individually how to price their policies. There are three ways they can set the price: community or no-age rated, issue-age rated or attained-age rated. Be sure and ask them how they do it, because the way they set the price affects how much you pay now and in the future.

Know What Medigap Policies Don't Cover:
Medigap policies don't cover long-term care, hearing aids, eyeglasses, private-duty nursing and prescription drugs, vision or dental care. Prescription drug coverage can be obtained by joining the Medicare Prescription Drug Plan, or Part D.
The important thing is to seek out experts and ask questions when looking to purchase Medigap insurance.