Want Medicare? Don't miss Wednesday's deadline

If you've been putting off enrolling in Medicare for next year, now is the time to act.

Open enrollment for Medicare Advantage and Part D prescription drug coverage is winding down. Eligible individuals have between Oct. 15 and Dec. 7 to make updates to their coverage for the following year. (One caveat: if you're still working past age 65 and are covered by your employer, you get a special enrollment period when you do retire.)

During that time, you can also switch from original Medicare, known as Part A hospital insurance and Part B medical coverage, to a private Medicare Advantage plan.

More than 55 million Americans are currently enrolled.

Over this seven-week period, you can also join a prescription drug plan, drop your coverage or swap Medicare Advantage plans. You can also just keep your current plan.

"You should know that it's not too late," said Katy Votava, founder of Goodcare.com, a Medicare consultancy. She said that while you can enroll through the entire day on Dec. 7, the government's website, Medicare.gov, will likely be slow.

Though President-elect Donald Trump has said he'd like to "modernize" the program, what may happen is still unknown.

Here's what you should know in the remaining hours to renew coverage for 2017.

Even though time is short, be sure to pull together a list of your providers and medications to ensure that you can still access them next year.

Talk with your doctor and make sure that he or she is on the same supplemental plan that you're on, said Carolyn McClanahan, a certified financial planner who began her career as a physician and is now president of Life Planning Partners in Jacksonville, Florida.

Don't just "phone in" your Part D plan selection for next year. Use the Medicare Plan Finder, an online wizard from the government that can help you decide which plan is best. You can also input details for your prescription drugs.

"Be prepared with your list of medications and make sure that they're covered," said Votava of Goodcare.com.

If you make the jump to Medicare Advantage, don't do it on the fly. You might not have access to the same doctors and hospitals.

"Make sure you can live with the limitations of Medicare Advantage," said McClanahan. Coverage through health maintenance organization plans, for instance, generally only give you access to providers who are in network.

"Your choices will be very limited, so be at peace with it," she said.

The plan you have now might not be the best choice for you next year. Insurers could change their cost structure for 2017, which may result in higher premiums, deductibles and copays.

In the event the company providing your Medicare Advantage or Part D plan does not renew its contract with Medicare for the new year, you'll have a grace period from Dec. 8 until the last day of February to join a new plan.

It's best to call the provider of your coverage to ensure they are still participating in Medicare next year, Goodcare.com's Votava said.

If you sign up for Medicare Advantage before the Dec. 7 deadline, but you decide you want to switch back to original Medicare, you can do so from Jan. 1 to Feb. 14.

This is called the Medicare Advantage Disenrollment Period.

If you revert to original Medicare, you'll have until Feb.14 to join a Part D drug plan. Votava also recommends picking up a Medigap policy to help cover additional costs.

Be aware that you can't swap between Medicare Advantage plans, switch out Part D drug plans or change from original Medicare to Medicare Advantage during the Jan. 1 to Feb. 14 period.

The jury is out as to how Medicare may change under Trump's incoming administration.

Speaker of the House Paul Ryan (R-Wis.) has backed proposals to provide "premium support payments" or vouchers for Medicare.

During his campaign, Trump said he wouldn't cut the program. However, his transition website says the president-elect will "modernize Medicare."

How the health insurance program will evolve under a new regime remains to be seen.