The Medicare Web site has a tool that makes it easy to find the best plan for you. By Kimberly Lankford, Contributing Editor August 27, 2012 If you’re age 65 or over, you have a slew of choices for filling the gaps in Medicare during open-enrollment season, which runs from October 15 to December 7. Most people choose either Medicare Part D prescription-drug coverage (to supplement a medigap policy) or a Medicare Advantage policy, which covers both medical and prescription-drug costs. The coverage and costs can change every year, and you have only eight weeks to make a decision that generally locks you in for a year. Medicare’s Plan Finder makes it easy to find out which plan is likely to offer the best deal. Type in your zip code and your drugs and dosages, and the tool shows how much you’d pay over a year in total out-of-pocket costs -- including premiums and co-payments. You can also input your general medical condition to compare the coverage and costs for the Medicare Advantage plans in your area (called “Medicare Health Plans”). A State Health Insurance Assistance Program (SHIP) representative can walk you through the tool and help find the best plan for you. Call 800-633-4227 or visit www.shiptalk.org for contact information. This article first appeared in Kiplinger's Personal Finance magazine. For more help with your personal finances and investments, please subscribe to the magazine. It might be the best investment you ever make.