Many insurers are shrinking provider networks, so make sure your doctors are included in the plans you're considering. By Kimberly Lankford, Contributing Editor From Kiplinger's Personal Finance, October 2014 I’ve had a Medicare Advantage plan for quite a while, but one of my favorite doctors just left the plan. I’d like to switch plans or go back to traditional Medicare and get a medigap policy. When can I switch? --C.W., via e-mailSee Also: 10 Things You Should Know About Medicare You can generally switch Medicare Advantage plans only during fall open enrollment: October 15 to December 7. Also, you can switch back to traditional Medicare within 12 months of first joining a Medicare Advantage plan. You can sign up for a five-star plan anytime during the year, but there’s a catch: Only 14 Medicare Advantage plans met this criteria in 2014. They’re available in certain counties in California, Colorado, Florida, Georgia, Hawaii, Illinois, Iowa, Maryland, Texas, Oregon, Virginia, Washington state, Wisconsin and in Washington, D.C. You can search for plans in your area with the Medicare PlanFinder. The five-star plans are designated with a special icon. Advertisement Otherwise, you must wait for open enrollment to switch coverage for 2015. Many insurers are shrinking provider networks, so make sure your doctors are included in the Medicare Advantage plans you’re considering. Also compare out-of-pocket costs for your drugs; some insurers charge 50% of the cost of certain brand-name drugs, and some boost costs unless you go to preferred pharmacies. Or you can switch to traditional Medicare, which covers more doctors. But first make sure you can also get a medigap policy, which covers Medicare’s deductibles and other coverage gaps. You could be rejected or charged more for medigap because of your health if it has been more than six months since you first signed up for Medicare Part B. Some states offer guaranteed-issue medigap policies, which you can get regardless of your health. Contact your State Health Insurance Assistance Program (www.shiptalk.org or 800-633-4227) or your state insurance department (www.naic.org) for details. You’ll also need to buy a Medicare Part D policy during open enrollment for prescription-drug coverage if you switch to traditional Medicare. See www.medicare.gov/find-a-plan. Got a question? Ask Kim at email@example.com.