You’ll get the best price if you sign up within six months after enrolling in Medicare Part B. During this open-enrollment period, an insurer cannot refuse to sell you a policy or charge you more because of your health.

You also need to be aware of the three pricing methods, which will affect your costs. Medigap policies are usually sold as either “attained-age” policies, which are premiums that start low but increase as you get older. “Issue-age” policies increase prices due to inflation, not age. These policies may start out a little more expensive than attained-age policies but generally have few rate increases over time. And “community-rate” policies, where everyone in an area is charged the same premium regardless of age. Issue-age and community-rated policies will usually save you money in the long-run.

No drug coverage

You also need to know that Medigap policies do not cover prescription drugs, so if you don’t have drug coverage, you need to consider buying a separate Medicare Part D drug plan too. You can compare plans and cost at medicare.gov/find-a-plan. Also note that Medigap plans do not cover vision or dental care, hearing aids or long-term care, either.

Alternative option

Instead of getting original Medicare, plus a Medigap policy and a separate Part D drug plan, you could sign up for a Medicare Advantage plan that provides all-in-one coverage. These plans, which are sold by insurance companies, are generally available through HMOs and PPOs. To find and compare Advantage plans visit medicare.gov/find-a-plan.

If you need help, contact your State Health Insurance Assistance Program (SHIP), which provides free Medicare counseling. See shiptalk.org, or call 800-677-1116 to locate a counselor in your area.

Send your senior questions to: Savvy Senior, P.O. Box 5443, Norman, OK 73070, or visit SavvySenior.org. Jim Miller is a contributor to the NBC Today show and author of “The Savvy Senior” book.