If you are about to be 65 or just turned 65, it’s time for you to look at Medicare. Three months before or after your 65th birthday, you can enroll. We are also in the final weeks of the annual Medicare open enrollment period where those eligible can join, drop or switch Medicare plans.

You might have seen the endless ads or be getting calls from insurance agents offering to enroll you in an Medicare Advantage program. But before you do that, consider the pros and cons.

As explained by Medicare. gov, Medicare Part A is hospital insurance and covers inpatient hospital care, lab tests, surgery and more; Medicare Part B is medical insurance, covering doctor and other health care providers’ services and outpatient care. Part A doesn’t cost you; Part B requires a monthly premium. You’re also likely to want to find a drug plan, Part D, for an additional cost.

Medicare Advantage plans are offered by private companies and include the components of original, or traditional, Medicare, namely Parts A and B, as well as a drug plan and typically services not covered by Medicare, such as dental and vision. Many Medicare Advantage programs have no premiums, which is enticing. (You’ll still have to pay your Part B premiums, though some Advantage plans might even pay part or all of that.)

But that doesn’t mean there are no costs. Under original Medicare, you typically pay 20% of the Medicare-approved amount for Part B services. You’re still paying under an Advantage plan, too, though plans might have higher or lower costs for certain services.

Plans do have an annual cap on what you’ll have to pay out of pocket, which varies from plan to plan. Advantage plans also typically limit which providers you can see. (Medicare supplement plans, are another option; they help cover the costs original Medicare doesn’t, but they don’t provide Part D or the other services found under Advantage plans.)

Sandee Wilson of Aspen Insurance Group (apsenins@ aol.com) points out to consumers, “If they choose to go with a Medicare Advantage plan, they can have out of pocket costs up to $8,950.” These plans might feel more like the health insurance plans for folks who are under age 65, which have a network of participating medical practices and include prescriptions. To have treatments covered by Medicare Advantage, you need to go to one of the providers in their network.

Wilson also cautions consumers, “If they get cancer or some other chronic disease and want to go to Mayo Clinic, Sloan Kettering, M.D. Anderson, etc., they may not be in their network and would not be able to go. If they get a chronic condition where treatment can be ongoing to several years, the out of pocket starts over every Jan. 1, so that zero dollar premium can put them on the hook for thousands of dollars each year.”

While it’s important to be aware of premiums, coverage is key. If you’re on Medicare Advantage and spend a lot of time in various places, be aware of what is available in network in all the locations.