The federal government requires Medicare Advantage plans, which are available from private insurers, to cover everything that original Medicare covers. Some plans pay for services that original Medicare doesn’t cover, such as routine dental, hearing and vision care. Most cover prescription medications. Medicare Advantage plans generally have a provider network.

The price you’ll pay for your medications with a Part D plan depends on whether they’re included in the plan’s formulary, which is its list of covered drugs, and the cost sharing required based on a drug’s pricing tier. Generic drugs tend to have the lowest cost sharing while brand name and specialty medications tend to be more expensive. You also may pay less if you use a pharmacy in the plan’s network.

After you enroll in Part B of Medicare at age 65 or older, you have six months to buy any Medigap policy in your area, no matter what your health problems may be. If you want to sign up or switch policies after that, insurers in many states can refuse to sell you a plan or charge you more because of preexisting conditions. Find out about any special Medigap rules in your state.