If you have original Medicare, most of the time you don’t have to worry about filing claims for reimbursement. However, Medicare Advantage and Medicare Part D rules are a bit different, and there are a few times when you may need to be reimbursed for out-of-pocket medical costs.

Continue reading to learn when you may need to file a Medicare claim and how to get reimbursed.

The Centers for Medicare and Medicaid (CMS) sets reimbursement rates for all medical services and equipment covered under Medicare. When a provider accepts assignment, they agree to accept Medicare-established fees.

Providers cannot bill you for the difference between their normal rate and Medicare set fees. The majority of Medicare payments are sent to providers of for Part A and Part B services.

Keep in mind, you are still responsible for paying any copayments, coinsurance, and deductibles you owe as part of your plan.

Next, we’ll review how reimbursement works with each part of Medicare.

Medicare Part A

Medicare Part A covers hospital services, hospice care, and limited home healthcare and skilled nursing care.

All your Part A–related expenses are covered by Medicare if you receive them through a participating provider who accepts Medicare assignment. You are responsible for your portion, including any copay, deductible, and coinsurance costs.

In some cases, you may need to file a claim if the facility fails to file the claim or if you receive a bill from a provider because the provider or supplier does not participate with Medicare.

You can check the status of all your covered expense claims in two ways:

  • through the Medicare summary notice mailed to you every 3 months
  • by logging into MyMedicare.gov to see the status of claims

Medicare Part B

Medicare Part B covers doctor’s visits, outpatient care, and preventive services.

Some nonparticipating doctors may not file a claim with Medicare and may bill you directly for services. When selecting a doctor, be sure they accept Medicare assignment. Nonparticipating providers can ask you to pay upfront and file a claim.

Medicare does not pay for services outside the United States except under special conditions like an emergency when a U.S. doctor or facility is not close by. Medicare determines these cases on an individual basis after you submit a claim.

Medicare will pay for services on board ships in medical emergencies or injury situations. You can file a claim if you have Part B, if the doctor treating you is authorized to practice in the United States, and if you are too far away from a U.S. facility when the emergency occurred.

Medicare Advantage (Part C)

Medicare Advantage or Part C works a bit differently since it is private insurance. In addition to Part A and Part B coverage, you can get extra coverage like dental, vision, prescription drugs, and more.

Most companies will file claims for services. Since Medicare Advantage is a private plan, you never file for reimbursement from Medicare for any outstanding amount. You will file a claim with the private insurance company to reimburse you if you have been billed directly for covered expenses.

There are several options for Part C plans including HMO and PPO. Each plan has in-network and out-of-network providers. Depending on the circumstances, if you see an out-of-network provider, you may have to file a claim to be reimbursed by the plan.

Be sure to ask the plan about coverage rules when you sign up. If you were charged for a covered service, you can contact the insurance company to ask how to file a claim.

Medicare Part D

Medicare Part D or prescription drug coverage is provided through private insurance plans. Each plan has its own set of rules on what drugs are covered. These rules or lists are called a formulary and what you pay is based on a tier system (generic, brand, specialty medications, etc.).

The pharmacy (retail or mail order) where you fill your prescriptions will file your claims for covered medications. You need to pay the copayment and any coinsurance. If you pay for a medication yourself, you cannot file a claim with Medicare. Any claims will be filed with your insurance provider.

when to file a claim for medications

Reasons you may need to file a claim for Part D medications include:

  • you paid for a vaccine that is covered
  • you traveled outside your plan area and ran out of medication and had to purchase them
  • you were given medication at an emergency room, outpatient surgery, or clinic by an out-of-network pharmacy during your “observation status”
  • you did not have access to your medicines due to a state or federal emergency or disaster and had to purchase them

In some cases, if the drug is notcovered or the cost is higher than you expect, you may need to ask the plan about coverage.

If you’ve paid for a medication, you can ask for a reimbursement by filling out a Model Coverage Determination Request Form. If you haven’t paid for the medication, you or your doctor can ask your plan for a “coverage determination” or an exception to get the medication covered. You can also file an appeal in writing to get the medication covered.


Medicare pays for 80 percent of your covered expenses. If you have original Medicare you are responsible for the remaining 20 percent by paying deductibles, copayments, and coinsurance.

Some people buy supplementary insurance or Medigap through private insurance to help pay for some of the 20 percent. There are 10 different plans that offer various coverage options.

Medigap will only pay for items approved by Medicare, and you cannot buy Medigap if you have a Medicare Advantage plan. There are no network restrictions with Medigap plans. If the provider accepts assignment, they accept Medigap.

If you go to a provider that accepts Medicare assignment, once the claim has been filed with Medicare, the balance may be paid by your Medigap plan. Remember to show your Medigap card along with your Medicare card to your provider at the time of service.

After Medicare pays its share, the balance is sent to the Medigap plan. The plan will then pay part or all depending on your plan benefits. You will also receive an explanation of benefits (EOB) detailing what was paid and when.

If you’ve been billed or had to pay upfront, you have 1 year from the date of service to file a claim for reimbursement.

Let’s look at the main types of Medicare providers for original Medicare (part A and B) and how reimbursement works.

Participating provider

Most providers fall under this category. They have signed a contract with Medicare to accept assignment. They agree to accept CMS set rates for covered services. Providers will bill Medicare directly, and you don’t have to file a claim for reimbursement.

In rare cases, a provider may fail or refuse to file a claim and may bill you directly for services; however, if they accept assignment, they are responsible for filing the claim. If you have tried to get the provider to file a claim and they refuse, you can report the issue by calling 800-MEDICARE or the Inspector General’s fraud hotline at 800-HHS-TIPS.

Opt-out provider

These providers do not accept Medicare and have signed a contract to be excluded. If you go to an opt-out provider, you must pay for all services. Rates may be higher than Medicare fees, and you cannot file a claim for these charges unless they are part of emergency medical care. You are responsible for paying the provider directly.

The provider should give you information about their charges. It’s a good idea to confirm that a provider accepts Medicare assignment to avoid higher or unexpected charges. Opt-out providers are the smallest category. One example of an opt-out provider is a psychiatrist, many of whom do not accept Medicare.

Nonparticipating provider

If the provider is not a participating provider, that means they don’t accept assignment. They may accept Medicare patients, but they have not agreed to accept the set Medicare rate for services.

This may mean you have to pay up to 15 percent more than the Medicare-approved rate for a service. States can limit this rate to a 5 percent upcharge, also called a “limiting charge.” This is the maximum amount that can be charged to Medicare patients after the 20 percent coinsurance. durable medical equipment (DME) does not fall under the limiting charge rule.

Some nonparticipating providers will bill Medicare, but others may ask you to pay them directly and file your own Medicare claim to be reimbursed.

Special circumstances

In some cases, a provider may ask you to sign an advance beneficiary notice (ABN), a liability waiver form that explains why a provider believes a specific service may not be covered byMedicare. The form must be very specific about why the provider believes aservice may not be covered. It cannot be a blanket general notice.

By signing the ABN, you agree to the expected fees and accept responsibility to pay for the service if Medicare denies reimbursement. Be sure to ask questions about the service and ask your provider to file a claim with Medicare first. If you don’t specify this, you will be billed directly.

As we mentioned earlier, it is rare for you to have to file a claim if you have original Medicare (part A and B) and the service provider is a participating provider.

Filing a claim is a relatively simple process. Just follow the steps listed below:

  1. Once you see the outstanding claims, first call the service provider to ask them to file the claim. If they cannot or will not file, you can download the form and file the claim yourself.
  2. Go to Medicare.gov and download the Patient Request of Medical Payment form CMS-1490-S.
  3. Fill out the form by carefully following the instructions provided. Explain in detail why you are filing a claim (doctor failed to file, supplier billed you, etc.), and provide the itemized bill with the provider’s name and address, diagnosis, the date and location of service (hospital, doctor’s office) and description of services.
  4. Provide any supporting information you think will be helpful for reimbursement.
  5. Be sure to make and keep a copy of everything you are submitting for your records.
  6. Mail the form to your Medicare contractor. You can check with the contractor directory to see where to send your claim. This is also listed by state on your Medicare Summary Notice, or you can call Medicare at 1-800-633-4227.
  7. Finally, if you need to designate someone else to file the claim or talk to Medicare for you, you need to fill out the “Authorization to Disclose Personal Health Information” form.

You can view any outstanding claims by checking your Medicare Summary Notice (mailed every 3 months) or by going to MyMedicare.gov.

Original Medicare pays for the majority (80 percent) of your Part A and Part B covered expenses if you visit a participating provider who accepts assignment. They will also accept Medigap if you have supplemental coverage. In this case, you will rarely need to file a claim for reimbursement.

You can keep track of all your pending claims by reviewing your Medicare summary notice online or when it comes in the mail. You have 1 year from the date of your service to file a claim if it was never filed by the provider.

In a few cases, you may have to pay for your services and file a claim to be reimbursed. The process is simple to follow, and help is available. If you have questions, you can call I-800-MEDICARE or contact your local State Health Insurance Assistance Program (SHIP).

You do not file Medicare claim forms if you have Medicare Advantage, Medigap or Medicare Part D private plans. Medigap is paid afterMedicare settles the claim. For Medicare Advantage and Part D private plans, you file directly with the plan. It is a good idea to call the plan and ask how to file a claim.