Among the significant reasons many people are mistaken about this is that there IS an annual enrollment period for Medicare Part D (prescription coverage) and Medicare Part C (Medicare Advantage), which people often mistakenly reference as a Medicare supplement. It is obviously not just a Medicare Supplement plan. For these kinds of plans, Medicare Part D and Medicare Part C, the enrollment period is November 15-December 31 of each year (this time frame is changing for 2011, but they're the dates for the 2010 annual election period).
Even given that, the conclusion of the year remains a great time for you to review your Medigap coverage and make any necessary changes. Medigap coverage doesn't change on an annual basis like Medicare Advantage and Medicare Part D. The plan coverage is the same over time; however, your rates can alter on an annual basis. Some companies change rates based on your age (this usually occurs around your birthday), other individuals change rates annually (this occurs 1/1 of each year), and other companies change rates on your policy anniversary date. Either way, whenever your rate changes, it's highly likely that you have the ability to switch to the same plan from an alternative company and save money in your coverage.
It's advisable to re-evaluate your Medicare Supplement / Medigap coverage on at the least a bi-annual basis, as insurance is just a rapidly changing field that will require one to keep yourself updated of current rates and trends. Within the last few year in many aspects of the united states, Medicare Supplement rates have actually gone down because of new companies entering the marketplace and new plans being released (Medigap Plan N). So, ultimately, although you don't need to re-evaluate your plan throughout the upcoming annual enrollment period, now is a good time to do so.