Now that you've enrolled in Medicare, you can take advantage of the program's benefits to help pay for your health care in retirement.

But before you make that first doctor's appointment, take a moment to learn about how Medicare works and what to expect when you use it.

These tips will walk you through the basics of navigating the system, choosing a health care provider, estimating your out-of-pocket costs and understanding the Medicare billing process.

Know Your Health Care Provider Options

Once you've enrolled in Medicare, you can select any doctor, hospital or provider that accepts Medicare patients. Visit the official Medicare website to find and compare Medicare-enrolled providers in your area. Unlike with many other health insurance plans, you don't have to set a primary care doctor when you're enrolled in Medicare. You also don't need a referral to see a specialist.

Medicare doesn't cover any care you receive from a provider that does not participate in Medicare, except in an emergency. If you receive health services from a provider that's opted out of Medicare, you'll have to pay for all of it.

Estimate Your Out-of-Pocket Costs

Though Medicare coverage is broad, it does not pay for 100% of your health care costs. Before the coverage begins, you must meet the deductible on Medicare Part A, your hospital insurance, and Medicare Part B, your medical insurance. For 2021, the Part A deductible is $1,484. The Part B deductible is $203.

Medicare Part A also charges a daily coinsurance for any hospital stay that lasts longer than 60 days. For 2021, the coinsurance charge is $371 per day for days 61 through 90. Any hospitalization beyond 90 days costs $742 a day.

After you meet the Part B deductible, you will usually pay 20% of the Medicare-approved costs for doctor services, outpatient therapy and durable medical equipment (devices that assist your daily activities at home).

The Your Medicare Benefits guidebook includes an A-to-X-rays listing of the items and services that Medicare covers, including how often they will be covered each year and how much, if anything, you will pay out-of-pocket.

If you get Medicare coverage through a Medicare Advantage plan, an alternative to Original Medicare, your out-of-pocket costs will be lower when you use the providers within the plan's network and service area.

Understand the Medicare Billing Process

When you receive care from a Medicare-enrolled provider under Medicare parts A and B, the provider submits a claim to Medicare to receive payment for those services. A Medicare administrator evaluates and processes each claim.

Most health care providers agree to receive payment directly from Medicare, accept the Medicare-approved amount for the service or equipment they provide and not bill patients for any amount above the Medicare deductible and coinsurance. This agreement is called assignment. A provider who accepts assignment won't bill you for your share of the cost until after Medicare has paid its portion.

Most doctors, providers and suppliers accept assignment. If yours does not, your out-of-pocket costs will likely be higher. For example, a doctor who doesn't accept assignment could charge you up to 15% more than the Medicare-approved amount for certain services.

Take Advantage of Medicare Resources

Now you know the basics of your benefits and how to use them once you've enrolled in Medicare.

You might have additional questions about the process when specific health care needs arise. Look to this website, your health care provider or the official Medicare website for the answers. Speaking to a Medicare expert can also help resolve any questions you might have.