More than 61 million Americans are insured through Medicare, the government health insurance program for seniors age 65 and older.

Though seniors receive hospital and medical insurance coverage through Medicare Part A and Part B, or what's known as Original Medicare, they may have more health care coverage needs that Original Medicare doesn't cover. In these situations, a Medicare Advantage Plan may be a good option. However, it's important to understand the benefits these plans offer — and potential Medicare advantage plan cost — before you sign up.

Medicare Advantage Benefits: An "All-in-One" Original Medicare Alternative

Medicare Advantage, or Medicare Part C, is an alternative to Original Medicare. You can opt for these Medicare-approved plans, which are offered by private insurers, to get your Medicare Part A and Part B coverage. These plans often include Medicare Part D or prescription drug coverage, which isn't offered under Original Medicare.

Like traditional health insurance, Medicare Advantage plans can differ based on the insurance provider, but most plans offer very similar benefits and coverage. In some cases, these Medicare Advantage plans may come with lower out-of-pocket costs than Original Medicare and provide additional benefits, such as dental, hearing and vision coverage, along with Part D benefits.

However, all these covered health care services come at a price. Understanding Medicare Advantage plan costs can help you choose the plan that best meets your health care needs.

Medicare Advantage Plan Cost: What You'll Pay for a Plan

Medicare Advantage plan cost can vary depending on the insurer, whether the plan charges a monthly premium or a deductible, and your co-payment amount or coinsurance percentage, which is the set amount you pay per visit or a set percentage you pay for covered services, respectively.

Most Medicare Advantage plans don't have a monthly premium, but with some plans, you may pay both a monthly premium and a monthly Part B premium, which covers your medical insurance. Different plans also may offer benefits that include paying for some or all of your Part B premium, but this varies by insurer.

There's also a yearly limit, or deductible, for what you'll pay out of pocket for covered Part A and Part B services. Once you reach this limit, you won't pay anything out of pocket for the rest of the year, and your insurer will pay for any covered services.

All of these factors depend on the plan type. There are four main types of Medicare Advantage Plans:

Health Maintenance Organization (HMO) Plans

In an HMO plan, you only can receive coverage from in-network health care providers (with the exception of emergency situations), which are hospitals, doctors and other providers your plan has an agreement with to provide services at a reduced cost. If you need prescription drug coverage, it's important to find an HMO plan that offers this benefit because you aren't allowed a separate Medicare Part D plan with an HMO plan.

Preferred Provider Organization (PPO) Plans

A PPO plan allows you to receive coverage from both in-network providers and out-of-network providers. However, if you go out of network, you'll have to pay more for these services. Though most PPO plans offer prescription drug coverage, if you join a plan that doesn't offer this coverage, you won't be able to get a separate Part D plan.

Private Fee-for-Service (PFFS) Plans

With these plans, you generally must go to a Medicare-approved health care provider who accepts your plan's payment terms. You can go to an out-of-network provider who agrees to treat you under Medicare's program rules, but you'll pay more out of pocket for this care. Unlike HMO and PPO plans, PFFS plans don't offer prescription drug coverage, meaning you'll need to get a separate Medicare Part D plan, which will add to your out-of-pocket costs.

Medical Savings Account (MSA) Plans

An MSA is a high-deductible plan combined with a medical savings account. These plans typically don't have provider networks, but you can typically go to any Medicare-approved provider. Many of these plans also don't come with prescription drug coverage, so you'll have to get a separate Medicare Part D plan. MSA plans are a bit more complex than other Medicare Advantage plans, but what's important to understand is that Medicare gives your plan a set amount each year to deposit into a medical savings account on your behalf. You then can use this money to pay for health care costs, including Part A and Part B covered services, which count toward your deductible. Once the money runs out, you'll have to pay for health care services out of pocket until you reach your deductible. From there, your plan will pay for any covered services.

Should You Get a Medicare Advantage Plan?

If you're 65 or older and weighing coverage options, a Medicare Advantage plan may be worth considering.

While Original Medicare can cover hospital and medical services, if you need more comprehensive coverage, a Medicare Advantage plan may better meet your needs. Just keep in mind there are several options. Each offers distinct health care benefits and variable out-of-pocket costs, depending on whether you go to an out-of-network doctor or need prescription drug coverage.

You can find and compare plans with Medicare's Plan Finder. Use this tool and do your own research to carefully compare benefits, monthly premiums, deductibles and the amount of coverage you need to find the right plan for you.