For older Americans, Social Security and Medicare work hand in hand to guarantee your financial security in retirement. Social Security generally acts as a "set it and forget it" program, with most of the effort that goes into making the most of your Social Security coverage coming at the beginning when you choose to claim your benefits.

A lot can change with your health from year to year, though, and that makes Medicare a much different story when it comes to reviewing your coverage regularly. The Medicare program acknowledges the value of looking at and adjusting your coverage by having an annual open enrollment period. Just like the year-end open enrollment that most private health plans offer, Medicare's open enrollment is designed to give participants the flexibility to tailor their coverage to their particular needs. Below, we'll look at the basics of how open enrollment works and what choices you have.

How's Medicare open enrollment different from initial enrollment?

Most people become eligible for Medicare when they turn 65, and regardless of where your birthday falls during the year, Medicare will let you enroll for the program as soon as you become eligible. Open enrollment is available to those who are already Medicare members as well -- for a limited time. Each year, open enrollment starts on Oct. 15, and it ends about seven and a half weeks later, on Dec. 7. The idea is to give you and your Medicare provider enough time to make changes that will go into effect Jan. 1.

Medicare enrollment form with a pen on top.

Image source: Getty Images.

What changes are allowed during Medicare open enrollment?

The idea behind Medicare open enrollment is to give you the chance to make changes to the healthcare coverage that you get under the program. Open enrollment isn't the only time you can make those changes, but it's the time at which you have the most flexibility. The things you can do during Medicare open enrollment include:

  • If you're covered under traditional Medicare, including Part A hospital coverage and Part B medical and outpatient coverage, then you can switch to a Medicare Advantage plan offered by a private insurance company.
  • Conversely, if you're covered under a Medicare Advantage plan, you can switch back to traditional Medicare coverage if you want.
  • Those who have Medicare coverage under Medicare Advantage can also switch to a different Medicare Advantage plan, even if it's with another private health insurer.
  • If you have Part D prescription drug coverage, you can switch drug plans either with your existing insurance company or with another company. You can also drop your Part D coverage entirely if you choose.
  • If you don't have Part D prescription drug coverage, you can sign up for a Part D plan during open enrollment.
  • Medicare Advantage plans often include drug coverage of their own, but open enrollment allows you to switch between plans with different levels of drug coverage. You can typically change drug coverage options within your existing Medicare Advantage plan, and if that requires either adding or dropping separate Part D drug coverage, you can do that at the same time.

What's involved in making a smart move during open enrollment?

Using Medicare open enrollment to maximum advantage means looking at your expected healthcare costs and making sure you get the most from your coverage. The variables involved include any monthly premiums you have to pay for coverage, co-pays and other amounts that you have to pay when you need medical care, and exactly what healthcare needs you're likely to have.

For example, one common thing that happens as people age is that they need more prescription drugs to treat medical conditions. Early in retirement, if you didn't have major prescription drug needs, you might have chosen a Part D drug policy that charged little or no monthly premium but offered minimal drug coverage. But if you were just diagnosed with a new condition that means that you'll need a lot more types of medications, then switching to a more comprehensive plan could save you money in the long run -- even if the premiums are higher.

With respect to traditional Medicare and Medicare Advantage, a lot depends on your comfort level with Medicare Advantage's limits. Traditional Medicare lets you visit any doctor who accepts Medicare patients, without networks to worry about. Medicare Advantage often involves using networks of providers in order to get maximum savings, and lower costs typically hinge on your being willing to stay in-network.

The clock is ticking

Making ends meet is a challenge for most older Americans, and making the right choices with Medicare is a critical part of your financial security. By using Medicare open enrollment to your full advantage, you'll put yourself in position to get as much out of the government's healthcare program as you can.