When you first reach age 65, you enroll in Medicare and make a number of choices about your coverage.For example, you will decide between Original Medicare and Medicare Advantage, whether to enroll in Medigap coverage, and maybe add a Part D (prescription) plan. All of these choices are aimed at helping you manage your healthcare costs, which can be significant during retirement.

But you shouldn’t stop there. Medicare coverage is not something that you decide once and forget about it. Each year, you face more than one opportunity to make changes to your Medicare plan, so that you can access certain networks or lower your out-of-pocket costs.

Medicare’s Annual Enrollment Period. Each fall, from October 15 to December, Medicare operates its Annual Enrollment Period. By October you should receive an Annual Notice of Change from your plan administrator, detailing any upcoming changes in your coverage or expenses, so that you can compare with other plans and enroll in a different one if necessary. But even if your plan isn’t changing, it’s always a good idea to shop around. A better plan might be available to you, but you won’t know if you don’t look.

Medicare Advantage Open Enrollment Period. Those who opted for a Medicare Advantage plan will face a second opportunity to make changes during the Open Enrollment Period from January 1 to March 31 each year. If you discover that your Advantage plan network has changed, feel that the out-of-pocket expenses are wrong for you, or wish to change anything else about your plan, you can compare with other Medicare Advantage plans during this time. You can also drop Advantage and go back to Original Medicare.

Special Enrollment Periods. At any point during the year, certain details of your life circumstances might change. If those circumstances meet certain standards, you might be eligible for a Special Enrollment Period to make changes to your Medicare plan outside of the usual enrollment windows. Check with your Medicare broker if you think you qualify, because changing your coverage when needed can potentially save you money or help you access the right type of care.

As you can see, Medicare enrollment is never static! That’s a good thing, because healthcare remains the top expense for most retirees after housing. So take advantage of every opportunity to re-examine your plan. You never know when a better deal might come along.