By The Kiplinger Washington Editors November 8, 2010 Even though Medicare covers the bulk of your medical expenses when you reach age 65, there are still a lot of gaps to fill, including co-payments, deductibles and the cost of prescription drugs. If you’re lucky enough to have retiree health insurance, that may be your best bet for plugging the holes. But it’s becoming very rare. Private Medicare Advantage plans are another option for medical and drug expenses, but many of those plans have been either leaving the business or raising premiums and reducing coverage as health reform shrinks their government subsidies. Plan N, a new medigap plan that was introduced in June, can be a good alternative. You must pay the $155 Medicare Part B deductible plus $20 for doctors’ office visits and $50 for the ER, but the premium savings could still put you ahead. Plus, you can use any doctor or hospital. Options and prices vary by state and age; see www.planprescriber.com or www.medicare.gov/find-a-plan. However, if you signed up for Medicare Part B more than six months ago, some insurance companies could reject you or raise rates based on your medical condition. You’ll need to get a separate Part D policy for prescription drugs, which aren’t covered by medigap policies, and the good news is the coverage is improving in 2011. Go to www.medicare.gov/find-a-plan to compare costs for your drugs and dosages.