Medicare is one of the biggest government programs in the U.S., and the vast majority of Americans 65 or older rely on Medicare to help them meet their healthcare needs. The program is vital for the financial security of older Americans, especially because healthcare costs usually rise as you age, amounting to hundreds of thousands of dollars over the course of a typical person's retirement years.

Medicare coverage includes a lot of benefits, ranging from hospital stays to doctor visits and other medical needs. But Medicare doesn't purport to cover everything, and even if you're on Medicare, you still need to be prepared to pay for some of your own healthcare costs. Below, we'll look at five key areas in which Medicare won't pick up the entire tab for your health needs.

1. Long-term care

One of the biggest and most important areas that Medicare doesn't address is long-term care. Although you can receive care in a skilled nursing facility for a period of up to 100 days, that's designed primarily to address the need for rehabilitation following a covered hospital visit. What most people think of as nursing home care, in which staff are available to handle nonmedical needs and the tasks of daily living, aren't covered under Medicare.

Medical monitoring equipment, with a hospital bed in the background.

Image source: Getty Images.

Even if you get a Medicare supplemental insurance policy, also known as Medigap coverage, you still won't have benefits for long-term care needs. Instead, you'll need special long-term care insurance if you want protection for these costs.

2. Ordinary dental care

Dental coverage is also something that Medicare leaves out. You won't receive benefits for routine cleanings, dental exams, fillings, dentures, and other ordinary dental care. Only a small number of emergency or complicated dental procedures are covered under Part A hospital insurance.

Unlike with long-term care, some supplemental Medicare policies offer dental coverage as an additional benefit. Similarly, some private insurers make dental coverage available through Medicare Advantage. Otherwise, you'll need to cover your dental costs yourself or find private dental insurance to go along with your traditional Medicare coverage.

3. Vision care

Medicare doesn't cover routine eye examinations for glasses or contact lenses. There are a few exceptions for corrective lenses following more complicated procedures like cataract surgery, but in most cases, you'll need to pay for corrective eyewear out of pocket.

As with dental care, some insurers offer vision care benefits. You might be able to get coverage either through supplemental Medicare policies or through Medicare Advantage.

4. A portion of your hospital costs

Part A hospital insurance under Medicare provides comprehensive coverage for the vast majority of costs related to inpatient care, including hospital stays and skilled nursing visits. But it doesn't cover every penny. Patients are responsible to cover a deductible amount for each benefit period, which for 2019 is $1,364. That's the only thing you'll need to pay for a stay up to 60 days, but beyond that, you'll also be responsible for a coinsurance payment of $341 per day for days 61 to 90, and $682 per day for up to 60 lifetime reserve days if your stay exceeds 90 days. For extremely long hospital stays, Medicare won't cover anything beyond 90 days once you've used up your 60 lifetime reserve days.

Medigap coverage often helps pay for deductibles and coinsurance payments, but getting additional protection for long hospital stays is tougher. Similarly, the insurer for a Medicare Advantage plan will often build the costs of deductibles and coinsurance into their premiums.

5. A portion of your medical costs

Part B medical insurance covers doctor visits and most outpatient services, but for most services, it covers only 80% of the cost. You're typically responsible for the other 20%. In addition, a $185 deductible applies for 2019. These costs don't apply to Medicare's annual wellness visit, although if your doctor orders extra tests or provides additional services during that visit, then the standard deductible and 20% coinsurance might apply.

One of the best features of supplemental insurance and Medicare Advantage is that they often include these costs as part of their coverage. With your 20% share being potentially unlimited, some extra protection is valuable.

Be smart about Medicare

Medicare is a valuable program that can save you thousands of dollars in healthcare costs in retirement. By knowing its limitations, you'll be able to take full advantage of the benefits that Medicare provides while making smart decisions about whether you need additional coverage through a supplemental Medicare policy, Medicare Advantage, or a private insurance provider.