Because Medicare Part A and Part B provide inadequate medical coverage -- you should probably purchase additional insurance. Your choices for supplemental Medicare insurance involve two different kinds of plans.

Both types of coverage offer additional insurance. You can choose the plan that is best suited to your needs. These policies will help cover costs not paid by Medicare Part A and Part B such as deductibles, co-payments and coinsurance.

If you choose a more comprehensive Medicare Advantage or Medigap plan -- you will get some coverage for prescription drugs, vision and/or dental.

The best Medicare supplement insurance provides coverage specific to your needs at an affordable price. The good news is that there is a big variety of Medicare supplements for individuals from many different providers of Medicare supplement insurance.

Medicare Advantage is privately sold insurance that is government subsidized and meant to supplement the benefits of Medicare Part A and B. In fact, you must be enrolled in both Medicare Part A and Part B to purchase Medicare Advantage insurance. Costs of these plans will vary greatly because it is the individual company which determines the fees -- not the government.

All plans will require that you be enrolled in both Medicare Part A and Medicare Part B and that you pay your Medicare Part B premiums.

Coverage Options and Dependencies For Medicare Advantage Medicare Advantage plans vary greatly. Your choices will depend on where you live. Most plans are managed-care plans (HMOs) although fee-for-service discount plans are also available in some areas. A PPO plan is also available.

Most plans -- but not all -- will provide supplemental prescription drug coverage Part D. Some plans -- but not all -- will provide supplemental vision care. Some plans -- but not all -- will provide supplemental dental care.

More options can be found in a Medicare Advantage plan than in a Medigap plan. However, unlike Medigap insurance policies, Medicare Advantage policies are not standardized -- making comparison of plans difficult and time consuming.

Your other option for supplementing the benefits of Medicare Part A and B is a MediGap insurance policy. Coverage Options and Dependencies for Medigap Insurance Medigap insurance policies are standardized and you have 10 levels of coverage to choose among.

Medigap Plan A provides the least amount of coverage while MediGap Plan J provides the most coverage -- with a range of options in between. However, it is important to note that beginning in January 2006, Plans H, I, and J will no longer be available to new enrollees.

The new Part D medicare prescription drug plan is also available as a stand alone supplement to Medigap policies. These plans vary by company and a comparison to your needs can be done to get the best plan for you. Again, only those already enrolled in Medicare Part A and Medicare Part B can purchase a Medigap or Medicare Advantage policy.

Anyone over 65 should sign on during the six-month open enrollment period immediately following your enrollment in Medicare Part B.