Millions of seniors rely on Medicare to cover their healthcare needs. But if you're new to Medicare, you may not understand how the program works -- and that could hurt you at some point or another. Here are five key facts about Medicare that will help you make the most of your benefits, both now and in the future.

1. It's not free

We tend to think of Medicare as a single program, when in reality, it has several distinct parts. Part A covers hospital visits and is generally free for enrollees. Parts B and D, however, which cover doctor visits and prescriptions, respectively, come at a cost. Additionally, you'll be on the hook for coinsurance, deductibles, and copayments when you receive treatment or medications under Medicare, so you'll need to budget for those expenses accordingly.

Doctor talking to older male patient


2. Your premium costs can change from year to year

Once you start paying your Medicare premiums, don't get too comfortable with them. Currently, the standard Part B premium is $134 a month, but that has the potential to increase over time. That said, if you're enrolled in Social Security by the time those premiums rise, you'll be protected by what's known as the program's "hold harmless" provision. Under this provision, your Social Security payments can't go down as the result of a Medicare increase, so if your benefits rise by $20 as part of the program's cost-of-living adjustments, but Medicare goes up by $30, you won't have to pay that additional $10 out of pocket provided your premiums are being deducted directly from your benefits.

3. You don't need to stick to the same drug plan once you sign up for one

The Part D drug plan you start out with doesn't have to be the one you retain for life. In fact, in many cases, it shouldn't be the same plan you use year after year. That's because plan formularies evolve annually, which means that you might get superior coverage for the drugs you take one year and less generous coverage the following year. Rather than settle on a single plan, aim to review your options annually so that you're getting the coverage you need.

4. You're entitled to a host of free annual services

Not everything you do under Medicare has to cost you money. The program offers a number of free services designed to help you keep tabs on your health. In fact, you're entitled to a free annual screening for conditions such as:

  • Cardiovascular disease
  • Depression
  • Diabetes
  • Glaucoma
  • Obesity
  • Prostate disease

You're also entitled to a free wellness visit each year with your doctor, as well as no-cost vaccines against ailments such as the flu.

5. You don't need to leave your house to receive medical care

Many seniors have mobility issues that make seeing doctors a cumbersome process. So, a large number of older folks forgo the care they need to avoid the hassle of getting to and from medial offices. Medicare, however, has a program in place to address this issue. It currently offers a telehealth service that allows you to consult with healthcare professionals via videoconference. Not only can these remote consultations cost less than your typical office visit, but they're often easier to schedule, which means you won't need to wait as long to get the medical advice you need.

Because healthcare is a major expense among seniors, it pays to read up on Medicare and understand how the program works. The more you know, the better positioned you'll be to take full advantage of those benefits when you need them.

Editor's note: A previous version of this article contained an incorrect number for the standard Part B premium.