The open enrollment period when you can sign up for a Medicare supplement insurance policy (also known as a Medigap policy) lasts for only six months after you turn 65. If you forget to enroll during this time period, the insurance company may refuse to cover you, based on your pre-existing health conditions. They may also be able to charge you more for the insurance.

Medigap Plans were set up to help you pay some of the expenses that are not covered by Medicare. These policies are sold by private insurance companies and are intended to supplement the Original Medicare Plan coverage. If you are in the Original Medicare Plan and you have a Medigap policy, then both your Medicare and your Medigap will pay their share of your covered health care expenses.

The benefits to having a Medigap policy include: Reduced out-of-pocket costs, Freedom to choose your own doctors, hospitals, and other health care providers, and Coverage for Medicare's deductibles and co-payments.

If you are interested in purchasing a Medigap policy, the best time to do it is during your Medigap open enrollment period. Your open enrollment period lasts for six months and begins on the first day of the month in which you have reached age 65 or older and you enrolled in Medicare Part B.

From the moment you enroll in Part B, your Medigap open enrollment period begins and can't be changed. Within this six month period of open enrollment, insurance companies are not allowed to use medical underwriting. This is good news for anyone desiring to enroll in a Medigap plan. During this time an insurance company must sell you any Medigap policy they offer. The insurance company cannot make you wait for your coverage to begin and they can't add extra charges because of any health problems, past or present.

It is important that you don't procrastinate if you are going to enroll. While you are allowed to apply early, prior to when your Medigap open enrollment period starts, the rules change once your open enrollment period ends. If you are trying to apply after your open enrollment period, an insurance company is allowed to use medical underwriting to approve your coverage and to set the price for your policy. Also, once you are approved, you will likely have fewer choices.

Under certain specific situations, you still have the right to purchase Medigap insurance even when your open enrollment has expired. In these specific circumstances, guaranteed issue rights, or Medigap protections, are granted. If you fall in this category, insurance companies are required by law to offer you Medigap insurance and cannot exclude you because of existing health problems.

One other option you have is to enroll in a Medicare Advantage plan. Medicare Advantage Plans are health plan options (like HMOs and PPOs) approved by Medicare and run by private companies. These plans are part of the Medicare Program and are sometimes called "Part C" or "MA plans." Medicare pays an amount for your care every month to these private health plans. Medicare Advantage Plans must follow rules set by Medicare. Medicare Advantage Plans are not supplemental insurance.

The best advice is to enroll in a Medicare Part B, and the Medigap plan of your choice, as soon after you turn 65. Then go enjoy your retirement years with peace of mind, knowing that you're covered should any health problems arise.