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Medicare Open Enrollment 2016: What You Need to Know

Karen Damato
It's the annual opportunity for retirees to swap coverage and maybe lower health costs.

Open enrollment for 2017 Medicare coverage began on Oct. 15. Here are key facts and places to find even more information.

What is Medicare open enrollment?

It’s an annual period when people with Medicare can change their coverage. For instance, that might involve switching from Original Medicare—Part A for hospital coverage and Part B for doctor visits—to a Medicare Advantage plan from a private insurer. It’s also possible, and sometimes a smart money move, to switch from one Medicare Advantage plan to another or move among Part D plans for prescription drug coverage.

When is Medicare open enrollment for 2017?

For coverage that starts Jan. 1, 2017, open enrollment runs from Oct. 15 to Dec. 7, 2016.

Do I have to do anything if I’ve already got a Medicare Part D drug plan?

No, but you should.

If you don’t request a change, your coverage this year will be automatically renewed. But switching to a different plan might give you better coverage that costs you less on the prescriptions you take. MONEY contributor Philip Moeller explains how to take advantage of this once-a-year opportunity to cut your drug costs.

The average monthly premium for Part D plans is expected to increase 9% for 2017, to $42.17, according to the Kaiser Family Foundation.

Read next: 5 Ways to Save on Medicare

One valuable resource is Medicare’s online Plan Finder, which shows you what you would pay for your current medications under the various plans available in your area. But you should also check key coverage details directly with any individual plan you are considering. Here are pointers on comparing Medicare Part D plans from the nonprofit Medicare Rights Center.

What should I know about choosing between Original Medicare and Medicare Advantage?

Typically, retirees will choose between Medicare Advantage and the combination of Original Medicare and a private Medigap supplement policy. Medicare Advantage plans can offer extra benefits, such as vision care and some limited dental care, for an attractive price. But a key trade-off is that they limit the doctors and other providers whose services are covered.

Here’s a suggested list of questions to ask before joining a Medicare Advantage plan, from the Medicare Rights Center.

Do people new to Medicare need to sign up during open enrollment?

No. The rules for first signing up for Medicare at age 65 or later are separate and complex, depending on factors including whether you have started Social Security and whether you or your spouse has coverage through a current employer.

For instance, if you’re already receiving Social Security benefits as you approach age 65, you’ll automatically get Original Medicare. If you have have not yet claimed Social Security—and waiting for a few years, up to age 70, is often a smart strategy—you need to contact Social Security, which handles Medicare enrollment, to sign up for the health benefit.

You can often hold off on Medicare if you have coverage from your or your spouse’s current employer—but there are exceptions, and, if you do wait to enroll, there will be a specific window of time when you will need to apply.

In all cases, read the rules carefully, because a mistake in timing could subject you to extra charges. Resources include the official Medicare & You handbook, Social Security’s Medicare resources, and MONEY’s guide to navigating the Medicare maze.

What will Medicare Part B premiums be in 2017?

That’s a simple question that doesn’t have a simple answer. For most Medicare recipients who have their monthly Medicare Part B premiums subtracted from their Social Security benefits, the annual increase in that Medicare charge can’t exceed any increase in their Social Security benefit. The 2017 Social Security cost-of-living adjustment (COLA) will be a scant 0.3%, which will typically go in full to added Medicare charges. But the Medicare Part B increase could top 20% for some people, including those who haven’t yet claimed Social Security and others who are subject to higher charges because of their higher incomes.